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Sample records for failed fuel detection

  1. Failed MTR Fuel Element Detect in a Sipping Tests

    SciTech Connect

    Zeituni, C.A.; Terremoto, L.A.A.; da Silva, J.E.R.

    2004-10-06

    This work describes sipping tests performed on Material Testing Reactor (MTR) fuel elements of the IEA-R1 research reactor, in order to find out which one failed in the core during a routine operation. Radioactive iodine isotopes {sup 131}I and {sup 133}I, employed as failure monitors, were detected in samples corresponding to the failed fuel element. The specific activity of each sample, as well as the average leaking rate, were measured for {sup 137}Cs. The nuclear fuels U{sub 3}O{sub 8} - Al dispersion and U - Al alloy were compared concerning their measured average leaking rates of {sup 137}Cs.

  2. Detection and analysis of particles with failed SiC in AGR-1 fuel compacts

    DOE PAGES

    Hunn, John D.; Baldwin, Charles A.; Gerczak, Tyler J.; ...

    2016-04-06

    As the primary barrier to release of radioactive isotopes emitted from the fuel kernel, retention performance of the SiC layer in tristructural isotropic (TRISO) coated particles is critical to the overall safety of reactors that utilize this fuel design. Most isotopes are well-retained by intact SiC coatings, so pathways through this layer due to cracking, structural defects, or chemical attack can significantly contribute to radioisotope release. In the US TRISO fuel development effort, release of 134Cs and 137Cs are used to detect SiC failure during fuel compact irradiation and safety testing because the amount of cesium released by a compactmore » containing one particle with failed SiC is typically ten or more times higher than that released by compacts without failed SiC. Compacts with particles that released cesium during irradiation testing or post-irradiation safety testing at 1600–1800 °C were identified, and individual particles with abnormally low cesium retention were sorted out with the Oak Ridge National Laboratory (ORNL) Irradiated Microsphere Gamma Analyzer (IMGA). X-ray tomography was used for three-dimensional imaging of the internal coating structure to locate low-density pathways through the SiC layer and guide subsequent materialography by optical and scanning electron microscopy. In addition, all three cesium-releasing particles recovered from as-irradiated compacts showed a region where the inner pyrocarbon (IPyC) had cracked due to radiation-induced dimensional changes in the shrinking buffer and the exposed SiC had experienced concentrated attack by palladium; SiC failures observed in particles subjected to safety testing were related to either fabrication defects or showed extensive Pd corrosion through the SiC where it had been exposed by similar IPyC cracking.« less

  3. Detection and analysis of particles with failed SiC in AGR-1 fuel compacts

    SciTech Connect

    Hunn, John D.; Baldwin, Charles A.; Gerczak, Tyler J.; Montgomery, Fred C.; Morris, Robert N.; Silva, Chinthaka M.; Demkowicz, Paul A.; Harp, Jason M.; Ploger, Scott A.

    2016-04-06

    As the primary barrier to release of radioactive isotopes emitted from the fuel kernel, retention performance of the SiC layer in tristructural isotropic (TRISO) coated particles is critical to the overall safety of reactors that utilize this fuel design. Most isotopes are well-retained by intact SiC coatings, so pathways through this layer due to cracking, structural defects, or chemical attack can significantly contribute to radioisotope release. In the US TRISO fuel development effort, release of 134Cs and 137Cs are used to detect SiC failure during fuel compact irradiation and safety testing because the amount of cesium released by a compact containing one particle with failed SiC is typically ten or more times higher than that released by compacts without failed SiC. Compacts with particles that released cesium during irradiation testing or post-irradiation safety testing at 1600–1800 °C were identified, and individual particles with abnormally low cesium retention were sorted out with the Oak Ridge National Laboratory (ORNL) Irradiated Microsphere Gamma Analyzer (IMGA). X-ray tomography was used for three-dimensional imaging of the internal coating structure to locate low-density pathways through the SiC layer and guide subsequent materialography by optical and scanning electron microscopy. In addition, all three cesium-releasing particles recovered from as-irradiated compacts showed a region where the inner pyrocarbon (IPyC) had cracked due to radiation-induced dimensional changes in the shrinking buffer and the exposed SiC had experienced concentrated attack by palladium; SiC failures observed in particles subjected to safety testing were related to either fabrication defects or showed extensive Pd corrosion through the SiC where it had been exposed by similar IPyC cracking.

  4. Identification of failed fuel element

    DOEpatents

    Fryer, Richard M.; Matlock, Robert G.

    1976-06-22

    A passive fission product gas trap is provided in the upper portion of each fuel subassembly in a nuclear reactor. The gas trap consists of an inverted funnel of less diameter than the subassembly having a valve at the apex thereof. An actuating rod extends upwardly from the valve through the subassembly to a point where it can be contacted by the fuel handling mechanism for the reactor. Interrogation of the subassembly for the presence of fission products is accomplished by lowering the fuel handling machine onto the subassembly to press down on the actuating rod and open the valve.

  5. Fail-safe storage rack for irradiated fuel rod assemblies

    DOEpatents

    Lewis, Donald R.

    1993-01-01

    A fail-safe storage rack is provided for interim storage of spent but radioactive nuclear fuel rod assemblies. The rack consists of a checkerboard array of substantially square, elongate receiving tubes fully enclosed by a double walled container, the outer wall of which is imperforate for liquid containment and the inner wall of which is provided with perforations for admitting moderator liquid flow to the elongate receiving tubes, the liquid serving to take up waste heat from the stored nuclear assemblies and dissipate same to the ambient liquid reservoir. A perforated cover sealing the rack facilitates cooling liquid entry and dissipation.

  6. Fail-safe storage rack for irradiated fuel rod assemblies

    DOEpatents

    Lewis, D.R.

    1993-03-23

    A fail-safe storage rack is provided for interim storage of spent but radioactive nuclear fuel rod assemblies. The rack consists of a checkerboard array of substantially square, elongate receiving tubes fully enclosed by a double walled container, the outer wall of which is imperforate for liquid containment and the inner wall of which is provided with perforations for admitting moderator liquid flow to the elongate receiving tubes, the liquid serving to take up waste heat from the stored nuclear assemblies and dissipate same to the ambient liquid reservoir. A perforated cover sealing the rack facilitates cooling liquid entry and dissipation.

  7. Fail-safe storage rack for fuel rod assemblies

    SciTech Connect

    Lewis, D.R.

    1991-12-31

    This report discusses a fail-safe storage rack which is provided for interim storage of spent but radioactive nuclear fuel rod assemblies. The rack consists of a checkerboard array of substantially square, elongate receiving tubes fully enclosed by a double walled container, the outer wall of which is imperforate for liquid containment and the inner wall of which is provided with perforations for admitting moderator liquid flow to the elongate receiving tubes, the liquid serving to take up waste heat from the stored nuclear assemblies and dissipate same to the ambient liquid reservoir. A perforated cover sealing the rack facilitates cooling liquid entry and dissipation.

  8. Fail-safe fire detection system

    NASA Technical Reports Server (NTRS)

    Bloam, E. T.

    1974-01-01

    Fire detection control system continually monitors its own integrity, automatically signals any malfunction, and separately signals fire in any zone being monitored. Should be of interest in fields of chemical and petroleum processing, power generation, equipment testing, and building protection.

  9. Categorization of failed and damaged spent LWR (light-water reactor) fuel currently in storage

    SciTech Connect

    Bailey, W.J.

    1987-11-01

    The results of a study that was jointly sponsored by the US Department of Energy and the Electric Power Research Institute are described in this report. The purpose of the study was to (1) estimate the number of failed fuel assemblies and damaged fuel assemblies (i.e., ones that have sustained mechanical or chemical damage but with fuel rod cladding that is not breached) in storage, (2) categorize those fuel assemblies, and (3) prepare this report as an authoritative, illustrated source of information on such fuel. Among the more than 45,975 spent light-water reactor fuel assemblies currently in storage in the United States, it appears that there are nearly 5000 failed or damaged fuel assemblies. 78 refs., 23 figs., 19 tabs.

  10. Fail-safe system for activity cooled supersonic and hypersonic aircraft. [using liquid hydrogen fuel

    NASA Technical Reports Server (NTRS)

    Jones, R. A.; Braswell, D. O.; Richie, C. B.

    1975-01-01

    A fail-safe-system concept was studied as an alternative to a redundant active cooling system for supersonic and hypersonic aircraft which use the heat sink of liquid-hydrogen fuel for cooling the aircraft structure. This concept consists of an abort maneuver by the aircraft and a passive thermal protection system (TPS) for the aircraft skin. The abort manuever provides a low-heat-load descent from normal cruise speed to a lower speed at which cooling is unnecessary, and the passive TPS allows the aircraft skin to absorb the abort heat load without exceeding critical skin temperature. On the basis of results obtained, it appears that this fail-safe-system concept warrants further consideration, inasmuch as a fail-safe system could possibly replace a redundant active cooling system with no increase in weight and would offer other potential advantages.

  11. Additional Studies of the Criticality Safety of Failed Used Nuclear Fuel

    SciTech Connect

    Marshall, William BJ J; Wagner, John C

    2013-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for periods potentially greater than 40 years. Extended storage (ES) time and irradiation to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, could result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. Criticality analyses are conducted considering representative UNF designs covering a range of enrichments and burnups in multiple cask systems. Prior work developed a set of failed fuel configuration categories and specific configurations were evaluated to understand trends and quantify the consequences of worst-case potential reconfiguration progressions. These results will be summarized here and indicate that the potential impacts on subcriticality can be rather significant for certain configurations (e.g., >20% keff). It can be concluded that the consequences of credible fuel failure configurations from ES or transportation following ES are manageable (e.g., <5% keff). The current work expands on these efforts and examines some modified scenarios and modified approaches to investigate the effectiveness of some techniques for reducing the calculated increase in keff. The areas included here are more realistic modeling of some assembly types and the effect of reconfiguration of some assemblies in the storage and transportation canister.

  12. Upgrade of the Resonance Ionization Mass Spectrometer for Precise Identification of Failed Fuel in a Fast Reactor

    SciTech Connect

    Iwata, Yoshihiro; Ito, Chikara; Harano, Hideki; Aoyama, Takafumi

    2011-12-13

    Isotopic analysis of krypton (Kr) and xenon (Xe) by resonance ionization mass spectrometry (RIMS) is an effective tool for identification of failed fuel in fast reactors to achieve their safety operation and high plant availability. Reliability of the failed fuel detection and location (FFDL) system depends on the precise determination of {sup 78}Kr/{sup 80}Kr, {sup 82}Kr/{sup 80}Kr and {sup 126}Xe/{sup 129}Xe isotopic ratios, which is mainly hampered by statistical errors for detection of the corresponding isotopes except {sup 82}Kr generated in large amounts during operation of fast reactors. In this paper, we report on improvements of the laser optical system of our spectrometer to increase the resonance ionization efficiency of Kr and Xe atoms, focusing on (i) utilization of the uniform YAG laser beam to improve the wavelength conversion efficiency of sum frequency generation and (ii) reflection of the ultraviolet light by a concave mirror to increase the photon density. The results indicate that our upgraded resonance ionization mass spectrometer has enough performance for isotopic analysis of Kr and Xe required in the Monju FFDL system.

  13. A health physics program for operation with failed nuclear fuel; Dealing with fleas

    SciTech Connect

    Warnock, R.V.; Cooper, T.L.; Bray, L.G.; Goldin, E.M.; Knapp, P.J.; Lewis, M.N.; Rigby, W.F. )

    1987-07-01

    The San Onofre Unit 3 nuclear plant suffered fuel cladding failures during its first fuel cycle. As a result, primary systems and parts of the station were contaminated with fleas--tiny highly radioactive, and highly mobile fuel fragments. This article describes the special health physics practices needed to control flea contamination and to evaluate skin doses when personnel contaminations occur. Included are descriptions of a modified Eberline RO-2 ion chamber survey instrument with enhance flea detection capabilities and a laundry monitor that is used to check protective clothing for fleas.

  14. Comparison of two inductive learning methods: A case study in failed fuel identification

    SciTech Connect

    Reifman, J.; Lee, J.C.

    1992-05-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  15. Comparison of two inductive learning methods: A case study in failed fuel identification

    SciTech Connect

    Reifman, J. ); Lee, J.C. . Dept. of Nuclear Engineering)

    1992-01-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  16. Autonomous Component Health Management with Failed Component Detection, Identification, and Avoidance

    NASA Technical Reports Server (NTRS)

    Davis, Robert N.; Polites, Michael E.; Trevino, Luis C.

    2004-01-01

    This paper details a novel scheme for autonomous component health management (ACHM) with failed actuator detection and failed sensor detection, identification, and avoidance. This new scheme has features that far exceed the performance of systems with triple-redundant sensing and voting, yet requires fewer sensors and could be applied to any system with redundant sensing. Relevant background to the ACHM scheme is provided, and the simulation results for the application of that scheme to a single-axis spacecraft attitude control system with a 3rd order plant and dual-redundant measurement of system states are presented. ACHM fulfills key functions needed by an integrated vehicle health monitoring (IVHM) system. It is: autonomous; adaptive; works in realtime; provides optimal state estimation; identifies failed components; avoids failed components; reconfigures for multiple failures; reconfigures for intermittent failures; works for hard-over, soft, and zero-output failures; and works for both open- and closed-loop systems. The ACHM scheme combines a prefilter that generates preliminary state estimates, detects and identifies failed sensors and actuators, and avoids the use of failed sensors in state estimation with a fixed-gain Kalman filter that generates optimal state estimates and provides model-based state estimates that comprise an integral part of the failure detection logic. The results show that ACHM successfully isolates multiple persistent and intermittent hard-over, soft, and zero-output failures. It is now ready to be tested on a computer model of an actual system.

  17. Why conventional detection methods fail in identifying the existence of contamination events.

    PubMed

    Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

    2016-04-15

    Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading.

  18. Glucose-6-phosphate dehydrogenase-derived NADPH fuels superoxide production in the failing heart

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the failing heart, NADPH oxidase and uncoupled NO synthase utilize cytosolic NADPH to form superoxide. NADPH is supplied principally by the pentose phosphate pathway, whose rate-limiting enzyme is glucose 6-phosphate dehydrogenase (G6PD). Therefore, we hypothesized that cardiac G6PD activation dr...

  19. Data Compilation for AGR-3/4 Designed-to-Fail (DTF) Fuel Particle Batch LEU04-02DTF

    SciTech Connect

    Hunn, John D; Miller, James Henry

    2008-10-01

    This document is a compilation of coating and characterization data for the AGR-3/4 designed-to-fail (DTF) particles. The DTF coating is a high density, high anisotropy pyrocarbon coating of nominal 20 {micro}m thickness that is deposited directly on the kernel. The purpose of this coating is to fail early in the irradiation, resulting in a controlled release of fission products which can be analyzed to provide data on fission product transport. A small number of DTF particles will be included with standard TRISO driver fuel particles in the AGR-3 and AGR-4 compacts. The ORNL Coated Particle Fuel Development Laboratory 50-mm diameter fluidized bed coater was used to coat the DTF particles. The coatings were produced using procedures and process parameters that were developed in an earlier phase of the project as documented in 'Summary Report on the Development of Procedures for the Fabrication of AGR-3/4 Design-to-Fail Particles', ORNL/TM-2008/161. Two coating runs were conducted using the approved coating parameters. NUCO425-06DTF was a final process qualification batch using natural enrichment uranium carbide/uranium oxide (UCO) kernels. After the qualification run, LEU04-02DTF was produced using low enriched UCO kernels. Both runs were inspected and determined to meet the specifications for DTF particles in section 5 of the AGR-3 & 4 Fuel Product Specification (EDF-6638, Rev.1). Table 1 provides a summary of key properties of the DTF layer. For comparison purposes, an archive sample of DTF particles produced by General Atomics was characterized using identical methods. This data is also summarized in Table 1.

  20. Fuel cell flooding detection and correction

    DOEpatents

    DiPierno Bosco, Andrew; Fronk, Matthew Howard

    2000-08-15

    Method and apparatus for monitoring an H.sub.2 -O.sub.2 PEM fuel cells to detect and correct flooding. The pressure drop across a given H.sub.2 or O.sub.2 flow field is monitored and compared to predetermined thresholds of unacceptability. If the pressure drop exists a threshold of unacceptability corrective measures are automatically initiated.

  1. Failed fuel monitoring and surveillance techniques for liquid metal cooled fast reactors

    SciTech Connect

    Lambert, J.D.B.; Mikaili, R.; Gross, K.C.; Strain, R.V.; Aoyama, T.; Ukai, S.; Nomura, S.; Nakae, N.

    1995-05-01

    The Experimental Breeder Reactor II (EBR-II) has been used as a facility for irradiation of LMR fuels and components for thirty years. During this time many tests of experimental fuel were continued to cladding breach in order to study modes of element failure; the methods used to identify such failures are described in a parallel paper. This paper summarizes experience of monitoring the delayed-neutron (DN) and fission-gas (FG) release behavior of a smaller number of elements that continued operation in the run-beyond-cladding-breach (RBCB) mode. The scope of RBCB testing, the methods developed to characterize failures on-line, and examples of DN/FG behavior are described.

  2. A scoping study of fission product transport from failed fuel during N Reactor postulated accidents

    SciTech Connect

    Hagrman, D.L.

    1988-01-01

    This report presents a scoping study of cesium, iodine, and tellurium behavior during a cold leg manifold break in the N Reactor. More detail about fission product behavior than has previously been available is provided and key parameters that control this behavior are identified. The LACE LA1 test and evidence from the Power Burst Facility Severe Fuel Damage tests are used to test the key model applied to determine aerosol behavior. Recommendations for future analysis are also provided. The primary result is that most of the cesium, iodine, and tellurium remains in the molten uranium fuel. Only 0.0035 of the total inventory is calculated to be released. Condensation of the most of the species of cesium and iodine that are released is calculated, with 0.998 of the released cesium and iodine condensing in the spacers and upstream end of the connector tubes. Most of the tellurium that is released condenses, but the chemical reaction of tellurium vapor with surfaces is also a major factor in the behavior of this element.

  3. Qualification of helium measurement system for detection of fuel failures in a BWR

    NASA Astrophysics Data System (ADS)

    Larsson, I.; Sihver, L.; Loner, H.; Grundin, A.; Helmersson, J.-O.; Ledergerber, G.

    2014-05-01

    There are several methods for surveillance of fuel integrity during the operation of a boiling water reactor (BWR). The detection of fuel failures is usually performed by analysis of grab samples of off-gas and coolant activities, where a measured increased level of ionizing radiation serves as an indication of new failure or degradation of an already existing one. At some nuclear power plants the detection of fuel failures is performed by on-line nuclide specific measurements of the released fission gases in the off-gas system. However, it can be difficult to distinguish primary fuel failures from degradation of already existing failures. In this paper, a helium measuring system installed in connection to a nuclide specific measuring system to support detection of fuel failures and separate primary fuel failures from secondary ones is presented. Helium measurements provide valuable additional information to measurements of the gamma emitting fission gases for detection of primary fuel failures, since helium is used as a fill gas in the fuel rods during fabrication. The ability to detect fuel failures using helium measurements was studied by injection of helium into the feed water systems at the Forsmark nuclear power plant (NPP) in Sweden and at the nuclear power plant Leibstadt (KKL) in Switzerland. In addition, the influence of an off-gas delay line on the helium measurements was examined at KKL by injecting helium into the off-gas system. By using different injection rates, several types of fuel failures with different helium release rates were simulated. From these measurements, it was confirmed that the helium released by a failed fuel can be detected. It was also shown that the helium measurements for the detection of fuel failures should be performed at a sampling point located before any delay system. Hence, these studies showed that helium measurements can be useful to support detection of fuel failures. However, not all fuel failures which occurred at

  4. Licensing topical report: the measurement and modelling of time-dependent fission product release from failed HTGR fuel particles under accident conditions

    SciTech Connect

    Myers, B.F.; Morrissey, R.E.

    1980-04-01

    The release of fission products from failed fuel particles was measured under simulated accident (core heatup) conditions. A generic model and specific model parameters that describe delayed fission product release from the kernels of failed HTGR fuel particles were developed from the experimental results. The release of fission products was measured from laser-failed BISO ThO/sub 2/ and highly enriched (HEU) TRISO UC/sub 2/ particles that had been irradiated to a range of kernel burnups. The burnups were 0.25, 1.4, and 15.7% FIMA for ThO/sub 2/ particles and 23.5 and 74% FIMA for UC/sub 2/ particles. The fission products measured were nuclides of xenon, iodine, krypton, tellurium, and cesium.

  5. Fuel Line Based Acoustic Flame-Out Detection System

    NASA Technical Reports Server (NTRS)

    Puster, Richard L. (Inventor); Franke, John M. (Inventor)

    1997-01-01

    An acoustic flame-out detection system that renders a large high pressure combustor safe in the event of a flame-out and possible explosive reignition. A dynamic pressure transducer is placed in the fuel and detects the stabilizing fuel pressure oscillations, caused by the combustion process. An electric circuit converts the signal from the combustion vortices, and transmitted to the fuel flow to a series of pulses. A missing pulse detector counts the pulses and continuously resets itself. If three consecutive pulses are missing, the circuit closes the fuel valve. With fuel denied the combustor is shut down or restarted under controlled conditions.

  6. Chemochromic Indicators for the Detection of Hypergolic Fuels

    NASA Technical Reports Server (NTRS)

    Santiago-Maldonado, E.; Captian, J.; Devor, R.

    2010-01-01

    The toxicity and hazard level associated with the use of hypergolic fuels necessitates the development of technology capable of detecting the presence of such fuels in a variety of different environments and conditions. The most commonly used sensors for the detection of hypergolic fuels are electrochemical in nature, which have serious limitations when used as area monitoring devices. Recent collaborative work between Kennedy Space Center and ASRC Aerospace has led to the development of indicators which exhibit a color change upon exposure to hydrazine under different conditions. The indicators under investigation on this developmental effort are para-dimethylaminobenzaldehyde (PDAB), various formulations of universal pH indicators, and potassium tetrachloroaurate (KAuCl4). These chemochromic indicators have been tested for the detection of hydrazine under various conditions: pure liquid fuel, aqueous fuel solution, saline aqueous fuel solutions, vapor fuel, and 3-month shelf life study, which included UV protection, thermal extremes, and normal storage conditions. The hypergolic fuel indicator test was conducted with the indicator impregnated into a wipe material to test the applicability of the indicator to be used to capture (absorb) and indicate the presence of hypergolic fuels. Each of the indicators performed well, with the universal pH indicator being the best candidate because of the visible response color change and the indicator stability after the shelf life study.

  7. Flashback detection sensor for lean premix fuel nozzles

    DOEpatents

    Thornton, Jimmy Dean; Richards, George Alan; Straub, Douglas L.; Liese, Eric Arnold; Trader, Jr., John Lee; Fasching, George Edward

    2002-08-06

    A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360.degree. detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

  8. A vector-based failure detection and isolation algorithm for a dual fail-operational redundant strapdown inertial measurement unit

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R.; Bailey, Melvin L.

    1987-01-01

    A vector-based failure detection and isolation technique for a skewed array of two degree-of-freedom inertial sensors is developed. Failure detection is based on comparison of parity equations with a threshold, and isolation is based on comparison of logic variables which are keyed to pass/fail results of the parity test. A multi-level approach to failure detection is used to ensure adequate coverage for the flight control, display, and navigation avionics functions. Sensor error models are introduced to expose the susceptibility of the parity equations to sensor errors and physical separation effects. The algorithm is evaluated in a simulation of a commercial transport operating in a range of light to severe turbulence environments. A bias-jump failure level of 0.2 deg/hr was detected and isolated properly in the light and moderate turbulence environments, but not detected in the extreme turbulence environment. An accelerometer bias-jump failure level of 1.5 milli-g was detected over all turbulence environments. For both types of inertial sensor, hard-over, and null type failures were detected in all environments without incident. The algorithm functioned without false alarm or isolation over all turbulence environments for the runs tested.

  9. Sedimentation studies on human amylin fail to detect low-molecular-weight oligomers.

    PubMed

    Vaiana, Sara M; Ghirlando, Rodolfo; Yau, Wai-Ming; Eaton, William A; Hofrichter, James

    2008-04-01

    Sedimentation velocity experiments show that only monomers coexist with amyloid fibrils of human islet amyloid-polypeptide. No oligomers containing <100 monomers could be detected, suggesting that the putative toxic oligomers are much larger than those found for the Alzheimer's peptide, Abeta(1-42).

  10. Family History Fails to Detect the Majority of Children with High Capillary Blood Total Cholesterol.

    ERIC Educational Resources Information Center

    Davidson, Dennis M.; And Others

    1991-01-01

    To examine the predictive value of family history in detecting children with high blood cholesterol, finger-stick screening was done in children (n=1,118) ages 9-10 with parental and grandparental history of cardiovascular disease and risk factors. Findings showed that screening only children with positive family histories will leave most problems…

  11. Technical Note: The single particle soot photometer fails to detect PALAS soot nanoparticles

    NASA Astrophysics Data System (ADS)

    Gysel, M.; Laborde, M.; Corbin, J. C.; Mensah, A. A.; Keller, A.; Kim, J.; Petzold, A.; Sierau, B.

    2012-07-01

    The single particle soot photometer (SP2) uses laser-induced incandescence (LII) for the measurement of atmospheric black carbon (BC) particles. The BC mass concentration is obtained by combining quantitative detection of BC mass in single particles with a counting efficiency of 100% above its lower detection limit (LDL). It is commonly accepted that a particle must contain at least several tenths of femtograms BC in order to be detected by the SP2. Here we show the unexpected result that BC particles from a PALAS spark discharge soot generator remain undetected by the SP2, even if their BC mass, as independently determined with an aerosol particle mass analyser (APM), is clearly above the typical LDL of the SP2. Comparison of counting efficiency and effective density data of PALAS soot with flame generated soot (combustion aerosol standard burner, CAST), fullerene soot and carbon black particles (Cabot Regal 400R) reveals that particle morphology can affect the SP2's LDL. PALAS soot particles are fractal-like agglomerates of very small primary particles with a low fractal dimension, resulting in a very low effective density. Such loosely-packed particles behave like "the sum of individual primary particles" in the SP2's laser. Accordingly, the PALAS soot particles remain undetected as the SP2's laser intensity is insufficient to heat the primary particles to vaporisation because of their small size (primary particle diameter ~5-10 nm). It is not surprising that particle morphology can have an effect on the SP2's LDL, however, such a dramatic effect as reported here for PALAS soot was not expected. In conclusion, the SP2's LDL at a certain laser power depends on total BC mass per particle for compact particles with sufficiently high effective density. However, for fractal-like agglomerates of very small primary particles and low fractal dimension, the BC mass per primary particle determines the limit of detection, independent of the total particle mass

  12. Detecting pin diversion from pressurized water reactors spent fuel assemblies

    DOEpatents

    Ham, Young S.; Sitaraman, Shivakumar

    2017-01-10

    Detecting diversion of spent fuel from Pressurized Water Reactors (PWR) by determining possible diversion including the steps of providing a detector cluster containing gamma ray and neutron detectors, inserting the detector cluster containing the gamma ray and neutron detectors into the spent fuel assembly through the guide tube holes in the spent fuel assembly, measuring gamma ray and neutron radiation responses of the gamma ray and neutron detectors in the guide tube holes, processing the gamma ray and neutron radiation responses at the guide tube locations by normalizing them to the maximum value among each set of responses and taking the ratio of the gamma ray and neutron responses at the guide tube locations and normalizing the ratios to the maximum value among them and producing three signatures, gamma, neutron, and gamma-neutron ratio, based on these normalized values, and producing an output that consists of these signatures that can indicate possible diversion of the pins from the spent fuel assembly.

  13. New PCR assay detects rare tooth fungi in wood where traditional approaches fail.

    PubMed

    Parfitt, David; Hynes, Juliet; Rogers, Hilary J; Boddy, Lynne

    2005-11-01

    Lu et al. (2002) described a method for identifying Hericium species by PCR, using the primers HT-U1 and HT-L1 which they specifically designed for this purpose. In our hands these primers do not appear to discriminate between tooth fungi and other wood decay species. Therefore PCR primers were designed that discriminated Creolophus cirrhatus from other species (HER2F/HER3R), and which discriminate Hericium alpestre, H. coralloides and H. erinaceus from other wood decay Ascomycota and Basidiomycota but not from each other (HER2F/HER2R). Using the HER2F/HER3R primers together with traditional isolation and direct incubation procedures, the location of C. cirrhatus in Turkey oak logs was mapped. The PCR approach often detected C. cirrhatus in locations where it was suspected to be, based on patterns of staining and decay, but where it was not revealed by isolation onto agar media, emphasising the value of adopting several approaches to unravel fungal community structure in wood.

  14. T cells detect intracellular DNA but fail to induce type I IFN responses: implications for restriction of HIV replication.

    PubMed

    Berg, Randi K; Rahbek, Stine H; Kofod-Olsen, Emil; Holm, Christian K; Melchjorsen, Jesper; Jensen, David G; Hansen, Anne Louise; Jørgensen, Louise B; Ostergaard, Lars; Tolstrup, Martin; Larsen, Carsten S; Paludan, Søren R; Jakobsen, Martin R; Mogensen, Trine H

    2014-01-01

    HIV infects key cell types of the immune system, most notably macrophages and CD4+ T cells. Whereas macrophages represent an important viral reservoir, activated CD4+ T cells are the most permissive cell types supporting high levels of viral replication. In recent years, it has been appreciated that the innate immune system plays an important role in controlling HIV replication, e.g. via interferon (IFN)-inducible restriction factors. Moreover, innate immune responses are involved in driving chronic immune activation and the pathogenesis of progressive immunodeficiency. Several pattern recognition receptors detecting HIV have been reported, including Toll-like receptor 7 and Retinoic-inducible gene-I, which detects viral RNA. Here we report that human primary T cells fail to induce strong IFN responses, despite the fact that this cell type does express key molecules involved in DNA signaling pathways. We demonstrate that the DNA sensor IFI16 migrates to sites of foreign DNA localization in the cytoplasm and recruits the signaling molecules stimulator of IFN genes and Tank-binding kinase, but this does not result in expression of IFN and IFN-stimulated genes. Importantly, we show that cytosolic DNA fails to affect HIV replication. However, exogenous treatment of activated T cells with type I IFN has the capacity to induce expression of IFN-stimulated genes and suppress HIV replication. Our data suggest the existence of an impaired DNA signaling machinery in T cells, which may prevent this cell type from activating cell-autonomous anti-HIV responses. This phenomenon could contribute to the high permissiveness of CD4+ T cells for HIV-1.

  15. Good sensitivity and specificity of ultrasound for detecting pseudotumors in 83 failed metal-on-metal hip replacements

    PubMed Central

    Lainiala, Olli; Elo, Petra; Reito, Aleksi; Pajamäki, Jorma; Puolakka, Timo; Eskelinen, Antti

    2015-01-01

    Background and purpose Ultrasound is used for imaging of pseudotumors associated with metal-on-metal (MoM) hips. Ultrasound has been compared with magnetic resonance imaging, but to date there have been no studies comparing ultrasound findings and revision findings. Methods We evaluated the sensitivity and specificity of preoperative ultrasound for detecting pseudotumors in 82 patients with MoM hip replacement (82 hips). Ultrasound examinations were performed by 1 of 3 musculoskeletal radiologists, and pseudotumors seen by ultrasound were retrospectively classified as fluid-filled, mixed-type, or solid. Findings at revision surgery were retrieved from surgical notes and graded according to the same system as used for ultrasound findings. Results Ultrasound had a sensitivity of 83% (95% CI: 63–93) and a specificity of 92% (CI: 82–96) for detecting trochanteric region pseudotumors, and a sensitivity of 79% (CI: 62–89) and a specificity of 94% (CI: 83–98) for detecting iliopsoas-region pseudotumors. Type misclassification of pseudotumors found at revision occurred in 8 of 23 hips in the trochanteric region and in 19 of 33 hips in the iliopsoas region. Interpretation Despite the discrepancy in type classification between ultrasound and revision findings, the presence of pseudotumors was predicted well with ultrasound in our cohort of failed MoM hip replacements. PMID:25582840

  16. Evaluation of Particle Counter Technology for Detection of Fuel Contamination Detection Utilizing Fuel System Supply Point

    DTIC Science & Technology

    2014-06-19

    VA : Coordinating Research Council, Inc. Vols. 2013 Aviation Technical Committee Meetings, May 2012. 10. Dallas, A .,Block, J., Klick, P., Grove, B ...utilizing Fuel System Supply Point Joel Schmitigal U S Army Tank Automotive Research DISTRIBUTION STATEMENT A . Approved for public release; distribution...AVAILABILITY STATEMENT Distribution Statement A . Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT In June 2013

  17. Supernova relic neutrinos and the supernova rate problem: Analysis of uncertainties and detectability of ONeMg and failed supernovae

    SciTech Connect

    Mathews, Grant J.; Hidaka, Jun; Kajino, Toshitaka; Suzuki, Jyutaro

    2014-08-01

    Direct measurements of the core collapse supernova rate (R{sub SN}) in the redshift range 0 ≤ z ≤ 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this 'supernova rate problem' by detecting the energy spectrum of supernova relic neutrinos with a next generation 10{sup 6} ton water Čerenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 ≤z ≤ 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R{sub SN} has large uncertainties ∼1.8{sub −0.6}{sup +1.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to ∼1.1{sub −0.4}{sup +1.0} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average

  18. On-line detection of key radionuclides for fuel-rod failure in a pressurized water reactor.

    PubMed

    Qin, Guoxiu; Chen, Xilin; Guo, Xiaoqing; Ni, Ning

    2016-08-01

    For early on-line detection of fuel rod failure, the key radionuclides useful in monitoring must leak easily from failing rods. Yield, half-life, and mass share of fission products that enter the primary coolant also need to be considered in on-line analyses. From all the nuclides that enter the primary coolant during fuel-rod failure, (135)Xe and (88)Kr were ultimately chosen as crucial for on-line monitoring of fuel-rod failure. A monitoring system for fuel-rod failure detection for pressurized water reactor (PWR) based on the LaBr3(Ce) detector was assembled and tested. The samples of coolant from the PWR were measured using the system as well as a HPGe γ-ray spectrometer. A comparison showed the method was feasible. Finally, the γ-ray spectra of primary coolant were measured under normal operations and during fuel-rod failure. The two peaks of (135)Xe (249.8keV) and (88)Kr (2392.1keV) were visible, confirming that the method is capable of monitoring fuel-rod failure on-line.

  19. High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family.

    PubMed

    Brelsford, A; Rodrigues, N; Perrin, N

    2016-01-01

    Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

  20. Nondestructive Crack Detection in a Fuel System Component

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay; Wincheski, Russell; Prosser, William; Russell, Richard; Devries, Robert; Engel, James; Ruffino, Norman

    2010-01-01

    The paper discusses development of various NDE techniques to detect cracks in A40 steel poppets used in a valve of the fuel system of the Space Shuttle Orbiter. The valve assembly experiences a severe high cycle fatigue environment during its operation. Cracks were discovered at the radius of the poppet flange. Experience shows that very small cracks or material anomalies do not cause failure in a single operation event. While the design is being modified to eliminate the issue, NDE has been used to screen the poppets for cracks before every use. Several surface flaw detection techniques were considered and a few NDE techniques were developed to provide NDE screening for the flaw detection. The primary method used was the eddy current testing. In the eddy current technique, the X-Y channel test data from the eddy current instrument was recorded as computer files. A Matlab data review and plotting application was developed to analyze the data files. The Matlab application provides much higher resolution than the eddy current instrument that was used to acquire the data. Other techniques that were used included ultrasonic surface wave and magnetic particle testing. A probability of detection (POD) study was undertaken to determine the 90/95 size for the eddy current technique. This study used specimens with same geometry and material as the poppet. Fatigue cracks were grown in these specimens. Information on results of the NDE techniques and results of the POD study are provided.

  1. Fuel leak detection apparatus for gas cooled nuclear reactors

    DOEpatents

    Burnette, Richard D.

    1977-01-01

    Apparatus is disclosed for detecting nuclear fuel leaks within nuclear power system reactors, such as high temperature gas cooled reactors. The apparatus includes a probe assembly that is inserted into the high temperature reactor coolant gaseous stream. The probe has an aperture adapted to communicate gaseous fluid between its inside and outside surfaces and also contains an inner tube for sampling gaseous fluid present near the aperture. A high pressure supply of noncontaminated gas is provided to selectively balance the pressure of the stream being sampled to prevent gas from entering the probe through the aperture. The apparatus includes valves that are operable to cause various directional flows and pressures, which valves are located outside of the reactor walls to permit maintenance work and the like to be performed without shutting down the reactor.

  2. Hypergolic fuel detection using Single Walled Nanotube Networks

    NASA Astrophysics Data System (ADS)

    Desai, Sharvil; Hewaparakrama, Kapila; Sumanasekera, Gamini

    2008-03-01

    Reliable and accurate detection of hypergolic fuels is vital to U. S. Missile Defense Agency. In this research a simple and highly sensitive SWNT network sensor was developed for real time monitoring of hydrazine leaks to ppm level concentrations. Upon exposure to hydrazine vapor, the resistance of n-type (after degassing) nanotubes is observed to decrease rapidly. The response time exhibits a linear dependence on the concentrations of the vapor. It was also found that the resistance of the sample can be recovered by pumping on the sample and exposing to UV light. The experimental results support chemical adsorption of hydrazine on SWNTs. Theoretical results of hydrazine-SWNT interaction [1] are compared with the experimental observations. Results of similar study on ammonia, dimethyl hydrazine, and naphthalene will also be presented. [1] Min Yu, C. S. Jayanthi, Shi-Yu Wu, APS 2008

  3. 46 CFR 154.709 - Cargo boil-off as fuel: Gas detection equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo boil-off as fuel: Gas detection equipment. 154.709 Section 154.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Equipment Cargo Pressure and Temperature Control § 154.709 Cargo boil-off as fuel: Gas detection...

  4. 46 CFR 154.709 - Cargo boil-off as fuel: Gas detection equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo boil-off as fuel: Gas detection equipment. 154.709 Section 154.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Equipment Cargo Pressure and Temperature Control § 154.709 Cargo boil-off as fuel: Gas detection...

  5. 46 CFR 154.709 - Cargo boil-off as fuel: Gas detection equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Cargo boil-off as fuel: Gas detection equipment. 154.709 Section 154.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Equipment Cargo Pressure and Temperature Control § 154.709 Cargo boil-off as fuel: Gas detection...

  6. Systems and methods for detecting a flame in a fuel nozzle of a gas turbine

    DOEpatents

    Kraemer, Gilbert Otto; Storey, James Michael; Lipinski, John; Mestroni, Julio Enrique; Williamson, David Lee; Marshall, Jason Randolph; Krull, Anthony

    2013-05-07

    A system may detect a flame about a fuel nozzle of a gas turbine. The gas turbine may have a compressor and a combustor. The system may include a first pressure sensor, a second pressure sensor, and a transducer. The first pressure sensor may detect a first pressure upstream of the fuel nozzle. The second pressure sensor may detect a second pressure downstream of the fuel nozzle. The transducer may be operable to detect a pressure difference between the first pressure sensor and the second pressure sensor.

  7. Gas detection for alternate-fuel vehicle facilities.

    PubMed

    Ferree, Steve

    2003-05-01

    Alternative fuel vehicles' safety is driven by local, state, and federal regulations in which fleet owners in key metropolitan [table: see text] areas convert much of their fleet to cleaner-burning fuels. Various alternative fuels are available to meet this requirement, each with its own advantages and requirements. This conversion to alternative fuels leads to special requirements for safety monitoring in the maintenance facilities and refueling stations. A comprehensive gas and flame monitoring system needs to meet the needs of both the user and the local fire marshal.

  8. Hypergolic fuel detection using individual single walled carbon nanotube networks

    NASA Astrophysics Data System (ADS)

    Desai, S. C.; Willitsford, A. H.; Sumanasekera, G. U.; Yu, M.; Tian, W. Q.; Jayanthi, C. S.; Wu, S. Y.

    2010-06-01

    Accurate and reliable detection of hypergolic fuels such as hydrazine (N2H4) and its derivatives is vital to missile defense, aviation, homeland security, and the chemical industry. More importantly these sensors need to be capable of operation at low temperatures (below room temperature) as most of the widely used chemical sensors operate at high temperatures (above 300 °C). In this research a simple and highly sensitive single walled carbon nanotube (SWNT) network sensor was developed for real time monitoring of hydrazine leaks to concentrations at parts per million levels. Upon exposure to hydrazine vapor, the resistance of the air exposed nanotubes (p-type) is observed to increase rapidly while that of the vacuum-degassed nanotubes (n-type) is observed to decrease. It was found that the resistance of the sample can be recovered through vacuum pumping and exposure to ultraviolet light. The experimental results support the electrochemical charge transfer mechanism between the oxygen redox couple of the ambient and the Fermi level of the SWNT. Theoretical results of the hydrazine-SWNT interaction are compared with the experimental observations. It was found that a monolayer of water molecules on the SWNT is necessary to induce strong interactions between hydrazine and the SWNT by way of introducing new occupied states near the bottom of the conduction band of the SWNT.

  9. Hypergolic fuel detection using individual single walled carbon nanotube networks

    SciTech Connect

    Desai, S. C.; Willitsford, A. H.; Sumanasekera, G. U.; Yu, M.; Jayanthi, C. S.; Wu, S. Y.; Tian, W. Q.

    2010-06-15

    Accurate and reliable detection of hypergolic fuels such as hydrazine (N{sub 2}H{sub 4}) and its derivatives is vital to missile defense, aviation, homeland security, and the chemical industry. More importantly these sensors need to be capable of operation at low temperatures (below room temperature) as most of the widely used chemical sensors operate at high temperatures (above 300 deg. C). In this research a simple and highly sensitive single walled carbon nanotube (SWNT) network sensor was developed for real time monitoring of hydrazine leaks to concentrations at parts per million levels. Upon exposure to hydrazine vapor, the resistance of the air exposed nanotubes (p-type) is observed to increase rapidly while that of the vacuum-degassed nanotubes (n-type) is observed to decrease. It was found that the resistance of the sample can be recovered through vacuum pumping and exposure to ultraviolet light. The experimental results support the electrochemical charge transfer mechanism between the oxygen redox couple of the ambient and the Fermi level of the SWNT. Theoretical results of the hydrazine-SWNT interaction are compared with the experimental observations. It was found that a monolayer of water molecules on the SWNT is necessary to induce strong interactions between hydrazine and the SWNT by way of introducing new occupied states near the bottom of the conduction band of the SWNT.

  10. To quiz or not to quiz: Formative tests help detect students at risk of failing the clinical anatomy course.

    PubMed

    Azzi, Alain J; Ramnanan, Christopher J; Smith, Jennifer; Dionne, Éric; Jalali, Alireza

    2015-01-01

    Through a modified team-based learning (TBL) in the anatomy pre-clerkship curriculum, formative evaluations are utilized in the University of Ottawa Faculty of Medicine to assess and predict students' outcomes on summative examinations. The purpose of this study was to determine the efficiency of formative assessments to predict student's performance on summative examinations, during the first two semesters of medical school. Formative assessments included multiple-choice quizzes (MCQ) for each laboratory session and a practical midterm examination (MIDTERM), while the summative assessment corresponded to the final practical examination (FINAL). A moderate correlation between MCQs and FINAL (r = 0.353 and 0.301, respectively), and strong correlation between MIDTERM and FINAL assessments (r = 0.688 and 0.610, respectively) were found in the first two semesters. The MIDTERM-FINAL correlations were enhanced for students who scored under 61% in the MIDTERM (r = 0.887 and 0.717, respectively). Despite limitations, mostly related to particularities of the used tests, the analysis revealed an efficient method to identify students at risk of failing the FINAL in a TBL-based anatomy program. Future developments include the elaboration of strategies to predict and support those underperforming students.

  11. Phase-space overlap measures. I. Fail-safe bias detection in free energies calculated by molecular simulation

    NASA Astrophysics Data System (ADS)

    Wu, Di; Kofke, David A.

    2005-08-01

    We consider ways to quantify the overlap of the parts of phase space important to two systems, labeled A and B. Of interest is how much of the A-important phase space lies in that important to B, and how much of B lies in A. Two measures are proposed. The first considers four total-energy distributions, formed from all combinations made by tabulating either the A-system or the B-system energy when sampling either the A or B system. Measures for A in B and B in A are given by two overlap integrals defined on pairs of these distributions. The second measure is based on information theory, and defines two relative entropies which are conveniently expressed in terms of the dissipated work for free-energy perturbation (FEP) calculations in the A →B and B →A directions, respectively. Phase-space overlap is an important consideration in the performance of free-energy calculations. To demonstrate this connection, we examine bias in FEP calculations applied to a system of independent particles in a harmonic potential. Systems are selected to represent a range of overlap situations, including extreme subset, subset, partial overlap, and nonoverlap. The magnitude and symmetry of the bias (A →B vs B →A) are shown to correlate well with the overlap, and consequently with the overlap measures. The relative entropies are used to scale the amount of sampling to obtain a universal bias curve. This result leads to develop a simple heuristic that can be applied to determine whether a work-based free-energy measurement is free of bias. The heuristic is based in part on the measured free energy, but we argue that it is fail-safe inasmuch as any bias in the measurement will not promote a false indication of accuracy.

  12. Update on the Us Army’s Fuel Contamination Detection Efforts

    DTIC Science & Technology

    2011-04-04

    Refueled and Flameouts Sheppard AFB Fuel Truck Filter Failed SAP (TX) 2 21 Apr 05 UH 60L No 1 Engine Fuel Bypass caution light illum and...Foreign Military Sales – 4 - AH-64 Super Absorbent Polymer • US Army – 1 - UH - 60L /M Unknown - Water and Particulates – 6 - MH-47 E Particulates and...and engines Ft. Campbell 12 22-Sep-08 MH-47E Reopened investigation/Contam discovered in Robertson Internal Tanks Ft. Campbell 13 7 Jan 009 UH -60M

  13. Failings of trauma-specific and related psychological tests in detecting post-traumatic stress disorder in forensic settings.

    PubMed

    Kleinman, Stuart B; Martell, Daniel

    2015-01-01

    Judges and juries tend to be particularly impressed by test data, especially quantitative test data. Psychometric tests specific for assessing the presence of post-traumatic stress disorder (PTSD) are commonly employed by forensic mental health evaluators. Most of these instruments, however, have been designed to detect PTSD in treatment or research, and not forensic, settings. Those who rely on these measures without adequate awareness of their often significant limits in correctly identifying malingering may induce finders of fact to inordinately confidently accept the presence of PTSD. This article reviews problematic structural and content components of trauma-specific and related instruments used to evaluate PTSD and discusses the utility of specific techniques liable to be used in forensic settings to "fool" these measures.

  14. Detecting the influence of fossil fuel and bio-fuel black carbon aerosols on near surface temperature changes

    NASA Astrophysics Data System (ADS)

    Jones, G. S.; Christidis, N.; Stott, P. A.

    2011-01-01

    Past research has shown that the dominant influence on recent global climate changes is from anthropogenic greenhouse gas increases with implications for future increases in global temperatures. One mitigation proposal is to reduce black carbon aerosol emissions. How much warming can be offset by controlling black carbon is unclear, especially as its influence on past climate has not been previously unambiguously detected. In this study observations of near-surface warming over the last century are compared with simulations using a climate model, HadGEM1. In the simulations black carbon, from fossil fuel and bio-fuel sources (fBC), produces a positive radiative forcing of about +0.25 Wm-2 over the 20th century, compared with +2.52 Wm-2 for well mixed greenhouse gases. A simulated warming of global mean near-surface temperatures over the twentieth century from fBC of 0.14 ± 0.1 K compares with 1.06 ± 0.07 K from greenhouse gases, -0.58 ± 0.10 K from anthropogenic aerosols, ozone and land use changes and 0.09 ± 0.09 K from natural influences. Using a detection and attribution methodology, the observed warming since 1900 has detectable influences from anthropogenic and natural factors. Fossil fuel and bio-fuel black carbon is found to have a detectable contribution to the warming over the last 50 yr of the 20th century, although the results are sensitive to the period being examined as fBC is not detected for the later fifty year period ending in 2006. The attributed warming of fBC was found to be consistent with the warming from fBC unscaled by the detection analysis. This study suggests that there is a possible significant influence from fBC on global temperatures, but its influence is small compared to that from greenhouse gas emissions.

  15. Many commercially available antibodies for detection of CHOP expression as a marker of endoplasmic reticulum stress fail specificity evaluation.

    PubMed

    Haataja, Leena; Gurlo, Tatyana; Huang, Chang-Jiang; Butler, Peter C

    2008-01-01

    Endoplasmic reticulum (ER) stress contributes to beta cell death in type 2 diabetes (T2DM). ER stress is characterized by increased level of ER stress markers such as C/EBP homologous protein (CHOP). Activation of CHOP leads to its translocation into the nucleus, where it induces cell death. We previously reported nuclear CHOP in pancreatic sections from T2DM, but not T1DM, and in human islet amyloid polypeptide (IAPP) transgenic rodent pancreatic sections. These studies underscore the importance of studying nuclear CHOP. We have observed inconsistency in the detection of CHOP antibodies reported in the literature and also in our own experiments. To investigate the specificity of CHOP antibodies, we first induced ER stress by tunicamycin in rat insulinoma (INS) cells and prepared nuclear and cytoplasmic fractions. Then we examined CHOP expression by Western blotting and immunocytochemistry using seven commercially available CHOP antibodies in INS cells and human IAPP (h-IAPP) transgenic rodent pancreatic tissue. These studies show that three commercially available CHOP antibodies out of seven tested were non-specific. In conclusion, we give recommendations for CHOP antibody selection and methods to verify CHOP antibody specificity. Also, we propose that the authors report the catalog and lot numbers of the CHOP antibodies used.

  16. Detecting the influence of fossil fuel and bio-fuel black carbon aerosols on near surface temperature changes

    NASA Astrophysics Data System (ADS)

    Jones, G. S.; Christidis, N.; Stott, P. A.

    2010-09-01

    Past research has shown that the dominant influence on recent global climate changes is from anthropogenic greenhouse gas increases with implications for future increases in global temperatures. One mitigation proposal is to reduce black carbon aerosol emissions. How much warming can be offset by the aerosol's control is unclear, especially as its influence on past climate has not been previously unambiguously detected. In this study observations of near-surface warming over the last century are compared with simulations using a climate model, HadGEM1. In the simulations black carbon, from fossil fuel and bio-fuel sources (fBC), produces a positive radiative forcing of about + 0.25 Wm-2 over the 20th century, compared with a little under + 2.5 Wm-2 for well mixed greenhouse gases. A simulated warming of global mean near-surface temperatures over the twentieth century from fBC of 0.14 ± 0.1 K compares with 1.06 ± 0.07 K from greenhouse gases, -0.58 ± 0.10 K from anthropogenic aerosols, ozone and land use changes and 0.09 ± 0.09 K from natural influences. Using a detection and attribution methodology, the observed warming since 1900 has detectable influences from anthropogenic and natural factors. Fossil fuel and bio-fuel black carbon is found to have a detectable contribution to the warming over the last 50 years of the 20th century, although the results are sensitive to a number of analysis choices, and fBC is not detected for the later fifty year period ending in 2006. The attributed warming of fBC was found to be consistent with the warming from the unscaled simulation. This study suggests that there is a possible significant influence from fBC on global temperatures, but its influence is small compared to that from greenhouse gas emissions.

  17. Fiber optic distributed chemical sensor for the real time detection of hydrocarbon fuel leaks

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Kempen, C.; Esterkin, Yan; Sun, Sunjian

    2015-09-01

    With the increase worldwide demand for hydrocarbon fuels and the vast development of new fuel production and delivery infrastructure installations around the world, there is a growing need for reliable hydrocarbon fuel leak detection technologies to provide safety and reduce environmental risks. Hydrocarbon leaks (gas or liquid) pose an extreme danger and need to be detected very quickly to avoid potential disasters. Gas leaks have the greatest potential for causing damage due to the explosion risk from the dispersion of gas clouds. This paper describes progress towards the development of a fast response, high sensitivity, distributed fiber optic fuel leak detection (HySense™) system based on the use of an optical fiber that uses a hydrocarbon sensitive fluorescent coating to detect the presence of fuel leaks present in close proximity along the length of the sensor fiber. The HySense™ system operates in two modes, leak detection and leak localization, and will trigger an alarm within seconds of exposure contact. The fast and accurate response of the sensor provides reliable fluid leak detection for pipelines, storage tanks, airports, pumps, and valves to detect and minimize any potential catastrophic damage.

  18. Detection of diesel fuel leakage from underground storage tank using time domain reflectometry

    NASA Astrophysics Data System (ADS)

    Barnett, Daniel A.

    The Environmental Protection Agency (EPA) has established regulations concerning the construction and maintenance of an underground storage tank (UST) system. These regulations also define the means and methods required to detect potential leaks. Leak detection methods defined as "other methods" can be used if specific requirements are achieved. We find in our study time domain reflectometry (TDR) can be used to detect leaks from an UST. The magnitudes of reflections measured by the TDR technique are used to calculate electrical properties of the soil. We find the introduction of diesel fuel, a light non-aqueous phase liquid (LNAPL), into the soil alters the physical and chemical properties of the soil and subsequently the electrical properties. We demonstrate the measured variance of electrical properties can be correlated to the changes of diesel fuel concentration. We find diesel fuel can be detected and changes of concentration can be measured using TDR.

  19. Study of fail-safe abort system for an actively cooled hypersonic aircraft, volume 2

    NASA Technical Reports Server (NTRS)

    Peeples, M. E.; Herring, R. L.

    1976-01-01

    Conceptual designs of a fail-safe abort system for hydrogen fueled actively cooled high speed aircraft are examined. The fail-safe concept depends on basically three factors: (1) a reliable method of detecting a failure or malfunction in the active cooling system, (2) the optimization of abort trajectories which minimize the descent heat load to the aircraft, and (3) fail-safe thermostructural concepts to minimize both the weight and the maximum temperature the structure will reach during descent. These factors are examined and promising approaches are evaluated based on weight, reliability, ease of manufacture and cost.

  20. Nondestructive Crack Detection in a Fuel System Component

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay; Ruffino, Norman; Wincheski, Russell; Prosser, William; Winfree, William; Russell, Richard; Bryson, Craig; Devries, Robert; Engel, James; Landy, James

    2010-01-01

    The presentation examines the background and objective of nondestructive crack detection, flow control valve assembly and poppet post flight evaluation, poppet properties. magnetic property characterization of lab data, NDE, eddy current inspection, simulation, eddy current criteria, poppet cycle testing and NDE criteria, and the use of ultrasonic surface wave for crack detection.

  1. Compton suppressed LaBr3 detection system for use in nondestructive spent fuel assay

    NASA Astrophysics Data System (ADS)

    Bender, S.; Heidrich, B.; Ünlü, K.

    2015-06-01

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr3, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as 137Cs and 140La, due to scattered interactions in the detector, which allowed more spectral features to be resolved. There was a

  2. A novel qPCR protocol for the specific detection and quantification of the fuel-deteriorating fungus Hormoconis resinae.

    PubMed

    Martin-Sanchez, Pedro M; Gorbushina, Anna A; Kunte, Hans-Jörg; Toepel, Jörg

    2016-07-01

    A wide variety of fungi and bacteria are known to contaminate fuels and fuel systems. These microbial contaminants have been linked to fuel system fouling and corrosion. The fungus Hormoconis resinae, a common jet fuel contaminant, is used in this study as a model for developing innovative risk assessment methods. A novel qPCR protocol to detect and quantify H. resinae in, and together with, total fungal contamination of fuel systems is reported. Two primer sets, targeting the markers RPB2 and ITS, were selected for their remarkable specificity and sensitivity. These primers were successfully applied on fungal cultures and diesel samples demonstrating the validity and reliability of the established qPCR protocol. This novel tool allows clarification of the current role of H. resinae in fuel contamination cases, as well as providing a technique to detect fungal outbreaks in fuel systems. This tool can be expanded to other well-known fuel-deteriorating microorganisms.

  3. Portable Rapid Test Fuel Tank Leak Detection System

    DTIC Science & Technology

    2010-04-01

    aspects of the bulk tank leak detection method . It is not intended to provide a thorough description of the principles behind the system or how the...no Does the Method detect the presence of water in the bottom of the tank? ( ) yes (X) no B-2 Principle of Operation What technique...rates of 0.10 gal/hr and 0.20 gal/hr with a very high PD and very low PFA. This provides a significant improvement over current methods technologically

  4. Method of locating a leaking fuel element in a fast breeder power reactor

    DOEpatents

    Honekamp, John R.; Fryer, Richard M.

    1978-01-01

    Leaking fuel elements in a fast reactor are identified by measuring the ratio of .sup.134 Xe to .sup.133 Xe in the reactor cover gas following detection of a fuel element leak, this ratio being indicative of the power and burnup of the failed fuel element. This procedure can be used to identify leaking fuel elements in a power breeder reactor while continuing operation of the reactor since the ratio measured is that of the gases stored in the plenum of the failed fuel element. Thus, use of a cleanup system for the cover gas makes it possible to identify sequentially a multiplicity of leaking fuel elements without shutting the reactor down.

  5. Determining plutonium mass in spent fuel using Cf-252 interrogation with prompt neutron detection

    SciTech Connect

    Hu, Jianwei; Tobin, Stephen J; Menlove, Howard O; Croft, Stephen

    2010-01-01

    {sup 252}Cf Interrogation with Prompt Neutron (CIPN) detection is proposed as one of 14 NDA techniques to determine Pu mass in spent fuel assemblies (FAs). CIPN is a low-cost and portable instrument, and it looks like a modified fork detector combined with an active interrogation source. Fission chamber (FC) is chosen as neutron detector because of its insensitivity to {gamma} radiation. The CIPN assay is comprised of two measurements, a background count and an active count, without and with the {sup 252}Cf source next to the fuel respectively. The net signal above background is primarily due to the multiplication of Cf source neutrons caused by the fissile content. The capability of CIPN to detect diversion and to determine fissile content was quantified using MCNPX simulations. New schemes were proposed (such as burnup and cooling time correction, etc.) and the results show that the fissile content of a target spent fuel assembly can be determined using CIPN signal.

  6. 46 CFR 154.709 - Cargo boil-off as fuel: Gas detection equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.709 Cargo boil-off as fuel: Gas detection equipment... alarm at the machinery control station and in the wheelhouse if the methane concentration reaches...

  7. 46 CFR 154.709 - Cargo boil-off as fuel: Gas detection equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.709 Cargo boil-off as fuel: Gas detection equipment... alarm at the machinery control station and in the wheelhouse if the methane concentration reaches...

  8. How Does a Failing School Stop Failing?

    ERIC Educational Resources Information Center

    Warren-Gross, Laura

    2009-01-01

    The author's school had just been labeled a failing school by No Child Left Behind when its new principal arrived in the fall of 2007. In this demoralizing climate, teachers can get frustrated and choose to give up, or they can rise to the challenge, create a plan for improvement, and plunge into uncharted waters. This article discusses how the…

  9. Methodology and Software for Gross Defect Detection of Spent Nuclear Fuel at the Atucha-I Reactor

    SciTech Connect

    Sitaraman, Shivakumar; Ham, Young S.; Gharibyan, Narek; Peixoto, Orpet J.M.

    2015-07-01

    At the Atucha-I pressurized heavy water reactor in Argentina, fuel assemblies in the spent fuel pools are stored by suspending them in two vertically stacked layers. This introduces the unique problem of verifying the presence of fuel in either layer without physically moving the fuel assemblies. Since much of the fuel is very old, Cerenkov viewing devices are often not very useful even for the top layer. Given that the facility uses both natural uranium and slightly enriched uranium at 0.85 w% {sup 235}U, and has been in operation since 1974, a wide range of burnups and cooling times can exist in any given pool. A spent fuel neutron counting tool consisting of a fission chamber, SFNC, has been used at the site to verify the presence of fuel up to burnups of 8000 MWd/t. At higher discharge burnups to levels up 11,000 MWd/t, the existing signal processing software of the tool was found to fail due to non-linearity of the source term with burnup. A new Graphical User Interface software package based on the LabVIEW platform was developed to predict expected neutron signals covering all ranges of burnups and cooling times and establish maps of expected signals at various pool locations. The algorithm employed in the software uses a set of transfer functions in a 47-energy group structure which are coupled with a 47-energy group neutron source spectrum based on various cooling times and burnups for each of the two enrichment levels. The database of the software consists of these transfer functions for the three different inter-assembly pitches that the fuel is stored in at the site. The transfer functions were developed for a 6 by 6 matrix of fuel assemblies with the detector placed at the center surrounded by four near neighbors, eight next nearest neighbors and so on for the 36 assemblies. These calculations were performed using Monte Carlo radiation transport methods. The basic methodology consisted of starting sources in each of the assemblies and tallying the

  10. Nonlinear characteristics and detection of combustion modes for a hydrocarbon fueled scramjet

    NASA Astrophysics Data System (ADS)

    Zhang, Cong; Yang, Qingchun; Chang, Juntao; Tang, Jingfeng; Bao, Wen

    2015-05-01

    An experimental investigation of combustion mode transition in a hydrocarbon fueled scramjet combustor model is reported under Mach number 2.1 and 2.5 inflow conditions. Three different combustion modes with respect to equivalence ratio are observed, namely, scramjet mode, weak ramjet mode and strong ramjet mode. The typical features of different combustion modes are analyzed by wall-pressures and one-dimensionally estimated Mach number distributions. The processes of combustion mode transitions show significant nonlinear characteristics. The static pressure and Mach number have discontinuous sudden changes as the mode transition occurs, especially near the fuel-supply region, emphasizing the importance of detection and control of combustion modes. The nonlinear characteristics of wall-pressures near the exit of the isolator can be used in the detection of different combustion modes. A series of experiments prove that this pressure-magnitude-based detection technique is feasible.

  11. Design and Operation of Equipment to Detect and Remove Water within Used Nuclear Fuel Storage Bottles

    SciTech Connect

    C.C. Baker; T.M. Pfeiffer; J.C. Price

    2013-09-01

    Inspection and drying equipment has been implemented in a hot cell to address the inadvertent ingress of water into used nuclear fuel storage bottles. Operated with telemanipulators, the system holds up to two fuel bottles and allows their threaded openings to be connected to pressure transducers and a vacuum pump. A prescribed pressure rebound test is used to diagnose the presence of moisture. Bottles found to contain moisture are dried by vaporization. The drying process is accelerated by the application of heat and vacuum. These techniques detect and remove virtually all free water (even water contained in a debris bed) while leaving behind most, if not all, particulates. The extracted water vapour passes through a thermoelectric cooler where it is condensed back to the liquid phase for collection. Fuel bottles are verified to be dry by passing the pressure rebound test.

  12. Can the envisaged reductions of fossil fuel CO2 emissions be detected by atmospheric observations?

    PubMed

    Levin, Ingeborg; Rödenbeck, Christian

    2008-03-01

    The lower troposphere is an excellent receptacle, which integrates anthropogenic greenhouse gases emissions over large areas. Therefore, atmospheric concentration observations over populated regions would provide the ultimate proof if sustained emissions changes have occurred. The most important anthropogenic greenhouse gas, carbon dioxide (CO(2)), also shows large natural concentration variations, which need to be disentangled from anthropogenic signals to assess changes in associated emissions. This is in principle possible for the fossil fuel CO(2) component (FFCO(2)) by high-precision radiocarbon ((14)C) analyses because FFCO(2) is free of radiocarbon. Long-term observations of (14)CO(2) conducted at two sites in south-western Germany do not yet reveal any significant trends in the regional fossil fuel CO(2) component. We rather observe strong inter-annual variations, which are largely imprinted by changes of atmospheric transport as supported by dedicated transport model simulations of fossil fuel CO(2). In this paper, we show that, depending on the remoteness of the site, changes of about 7-26% in fossil fuel emissions in respective catchment areas could be detected with confidence by high-precision atmospheric (14)CO(2) measurements when comparing 5-year averages if these inter-annual variations were taken into account. This perspective constitutes the urgently needed tool for validation of fossil fuel CO(2) emissions changes in the framework of the Kyoto protocol and successive climate initiatives.

  13. Feasibility study of a mini fuel cell to detect interference from a cellular phone

    NASA Astrophysics Data System (ADS)

    Abdullah, M. O.; Gan, Y. K.

    Fuel cells produce electricity without involving combustion processes. They generate no noise, vibration or air pollution and are therefore suitable for use in many vibration-free power-generating applications. In this study, a mini alkaline fuel cell signal detector system has been designed, constructed and tested. The initial results have shown the applicability of such system for used as an indicator of signal disturbance from cellular phones. A small disturbance even at 4 mV cm -1, corresponding to an amplitude of 12-18 mG in terms of electromagnetic field, can be well detected by such a device. Subsequently, a thermodynamics model has been developed to provide a parametric study by simulation to show the likely performance of the fuel cell alone in other environments. As such the model can provide many useful generic design data for alkaline fuel cells. Two general conclusions can be drawn from the present theoretical study: (i) fuel cell performance increases with temperature, pressure and correction factor, C f; (ii) the temperature factor (E/ T) increases with increasing temperature and with increasing pressure factor.

  14. Detection and measurement of middle-distillate fuel vapors by use of tunable diode lasers.

    PubMed

    McNesby, K L; Wainner, R T; Daniel, R G; Skaggs, R R; Morris, J B; Miziolek, A W; Jackson, W M; McLaren, I A

    2001-02-20

    A sensor for the rapid (10-ms response time) measurement of vapors from the hydrocarbon-based fuels JP-8, DF-2, and gasoline is described. The sensor is based on a previously reported laser-mixing technique that uses two tunable diode lasers emitting in the near-infrared spectral region [Appl. Opt. 39, 5006 (2000)] to measure concentrations of gases that have unstructured absorption spectra. The fiber-mixed laser beam consists of two wavelengths: one that is absorbed by the fuel vapor and one that is not absorbed. Sinusoidally modulating the power of the two lasers at the same frequency but 180 degrees out of phase allows a sinusoidal signal to be generated at the detector (when the target gas is present in the line of sight). The signal amplitude, measured by use of standard phase-sensitive detection techniques, is proportional to the fuel-vapor concentration. Limits of detection at room temperature are reported for the vapors of the three fuels studied. Improvements to be incorporated into the next generation of the sensor are discussed.

  15. Study of a fail-safe abort system for an actively cooled hypersonic aircraft. Volume 1: Technical summary

    NASA Technical Reports Server (NTRS)

    Pirello, C. J.; Herring, R. L.

    1976-01-01

    Conceptual designs of a fail-safe abort system for hydrogen fueled actively cooled high speed aircraft are examined. The fail-safe concept depends on basically three factors: (1) a reliable method of detecting a failure or malfunction in the active cooling system, (2) the optimization of abort trajectories which minimize the descent heat load to the aircraft, and (3) fail-safe thermostructural concepts to minimize both the weight and the maximum temperature the structure will reach during descent. These factors are examined and promising approaches are evaluated based on weight, reliability, ease of manufacture and cost.

  16. Monte Carlo characterization of PWR spent fuel assemblies to determine the detectability of pin diversion

    NASA Astrophysics Data System (ADS)

    Burdo, James S.

    This research is based on the concept that the diversion of nuclear fuel pins from Light Water Reactor (LWR) spent fuel assemblies is feasible by a careful comparison of spontaneous fission neutron and gamma levels in the guide tube locations of the fuel assemblies. The goal is to be able to determine whether some of the assembly fuel pins are either missing or have been replaced with dummy or fresh fuel pins. It is known that for typical commercial power spent fuel assemblies, the dominant spontaneous neutron emissions come from Cm-242 and Cm-244. Because of the shorter half-life of Cm-242 (0.45 yr) relative to that of Cm-244 (18.1 yr), Cm-244 is practically the only neutron source contributing to the neutron source term after the spent fuel assemblies are more than two years old. Initially, this research focused upon developing MCNP5 models of PWR fuel assemblies, modeling their depletion using the MONTEBURNS code, and by carrying out a preliminary depletion of a ¼ model 17x17 assembly from the TAKAHAMA-3 PWR. Later, the depletion and more accurate isotopic distribution in the pins at discharge was modeled using the TRITON depletion module of the SCALE computer code. Benchmarking comparisons were performed with the MONTEBURNS and TRITON results. Subsequently, the neutron flux in each of the guide tubes of the TAKAHAMA-3 PWR assembly at two years after discharge as calculated by the MCNP5 computer code was determined for various scenarios. Cases were considered for all spent fuel pins present and for replacement of a single pin at a position near the center of the assembly (10,9) and at the corner (17,1). Some scenarios were duplicated with a gamma flux calculation for high energies associated with Cm-244. For each case, the difference between the flux (neutron or gamma) for all spent fuel pins and with a pin removed or replaced is calculated for each guide tube. Different detection criteria were established. The first was whether the relative error of the

  17. Microbial fuel cells applied to the metabolically based detection of extraterrestrial life.

    PubMed

    Abrevaya, Ximena C; Mauas, Pablo J D; Cortón, Eduardo

    2010-12-01

    Since the 1970s, when the Viking spacecrafts carried out experiments to detect microbial metabolism on the surface of Mars, the search for nonspecific methods to detect life in situ has been one of the goals of astrobiology. It is usually required that a methodology detect life independently from its composition or form and that the chosen biological signature point to a feature common to all living systems, such as the presence of metabolism. In this paper, we evaluate the use of microbial fuel cells (MFCs) for the detection of microbial life in situ. MFCs are electrochemical devices originally developed as power electrical sources and can be described as fuel cells in which the anode is submerged in a medium that contains microorganisms. These microorganisms, as part of their metabolic process, oxidize organic material, releasing electrons that contribute to the electric current, which is therefore proportional to metabolic and other redox processes. We show that power and current density values measured in MFCs that use microorganism cultures or soil samples in the anode are much larger than those obtained with a medium free of microorganisms or sterilized soil samples, respectively. In particular, we found that this is true for extremophiles, which have been proposed as potential inhabitants of extraterrestrial environments. Therefore, our results show that MFCs have the potential to be used for in situ detection of microbial life.

  18. A laminar flow microfluidic fuel cell for detection of hexavalent chromium concentration

    PubMed Central

    Ye, Dingding; Yang, Yang; Li, Jun; Zhu, Xun; Liao, Qiang; Zhang, Biao

    2015-01-01

    An electrochemical hexavalent chromium concentration sensor based on a microfluidic fuel cell is presented. The correlation between current density and chromium concentration is established in this report. Three related operation parameters are investigated, including pH values, temperature, and external resistance on the sensor performance. The results show that the current density increases with increasing temperature and the sensor produces a maximum regression coefficient at the catholyte pH value of 1.0. Moreover, it is found that the external resistance has a great influence on the linearity and current densities of the microfluidic sensor. Owing to the membraneless structure and the steady co-laminar flow inside the microchannel, the microfluidic sensor exhibits short response time to hexavalent chromium concentration. The laminar flow fuel cell sensor provides a new and simple method for detecting hexavalent chromium concentration in the industrial wastewater. PMID:26649130

  19. Who Really Failed? Commentary

    ERIC Educational Resources Information Center

    Maiuri, Katherine M.; Leon, Raul A.

    2012-01-01

    Scott Jaschik's (2010) article "Who Really Failed?" details the experience of Dominique Homberger, a tenured faculty member at Louisiana State University (LSU) who was removed from teaching her introductory biology course citing student complaints in regards to "the extreme nature" of the grading policy. This removal has…

  20. Color-Changing Sensors for Detecting the Presence of Hypergolic Fuels

    NASA Technical Reports Server (NTRS)

    Roberson, Luke; Captain, Janine; Santiago-Maldonado, Edgardo; Starr, Stanley; DeVor, Robert

    2013-01-01

    Hypergolic fuel sensors were designed to incorporate novel chemochromic pigments into substrates for use in various methods of leak detection. There are several embodiments to this invention that would provide specific visual indication of hypergols used during and after transfer. The ability to incorporate these pigments into various polymer matrices provides a unique opportunity to manufacture nearly any type of sensor shape that is required. The vibrant color change from yellow to black instantaneously shows the worker the presence of hypergols in the area.

  1. An evaluation of image based techniques for wildfire detection and fuel mapping

    NASA Astrophysics Data System (ADS)

    Gabbert, Dustin W.

    Few events can cause the catastrophic impact to ecology, infrastructure, and human safety of a wildland fire along the wildland urban interface. The suppression of natural wildland fires over the past decade has caused a buildup of dry, dead surface fuels: a condition that, coupled with the right weather conditions, can cause large destructive wildfires that are capable of threatening both ancient tree stands and manmade infrastructure. Firefighters use fire danger models to determine staffing needs on high fire risk days; however models are only as effective as the spatial and temporal density of their observations. OKFIRE, an Oklahoma initiative created by a partnership between Oklahoma State University and the University of Oklahoma, has proven that fire danger assessments close to the fire - both geographically and temporally - can give firefighters a significant increase in their situational awareness while fighting a wildland fire. This paper investigates several possible solutions for a small Unmanned Aerial System (UAS) which could gather information useful for detecting ground fires and constructing fire danger maps. Multiple fire detection and fuel mapping programs utilize satellites, manned aircraft, and large UAS equipped with hyperspectral sensors to gather useful information. Their success provides convincing proof of the utility that could be gained from low-altitude UAS gathering information at the exact time and place firefighters and land managers are interested in. Close proximity, both geographically and operationally, to the end can reduce latency times below what could ever be possible with satellite observation. This paper expands on recent advances in computer vision, photogrammetry, and infrared and color imagery to develop a framework for a next-generation UAS which can assess fire danger and aid firefighters in real time as they observe, contain, or extinguish wildland fires. It also investigates the impact information gained by this

  2. An Evaluation of Image Based Techniques for Early Wildfire Detection and Fuel Mapping

    SciTech Connect

    Gabbert, Dustin W.

    2015-05-01

    Few events can cause the catastrophic impact to ecology, infrastructure, and human safety of a wildland fire along the wildland urban interface. The suppression of natural wildland fires over the past decade has caused a buildup of dry, dead surface fuels: a condition that, coupled with the right weather conditions, can cause large destructive wildfires that are capable of threatening both ancient tree stands and manmade infrastructure. Firefighters use fire danger models to determine staffing needs on high fire risk days; however models are only as effective as the spatial and temporal density of their observations. OKFIRE, an Oklahoma initiative created by a partnership between Oklahoma State University and the University of Oklahoma, has proven that fire danger assessments close to the fire – both geographically and temporally – can give firefighters a significant increase in their situational awareness while fighting a wildland fire. This paper investigates several possible solutions for a small Unmanned Aerial System (UAS) which could gather information useful for detecting ground fires and constructing fire danger maps. Multiple fire detection and fuel mapping programs utilize satellites, manned aircraft, and large UAS equipped with hyperspectral sensors to gather useful information. Their success provides convincing proof of the utility that could be gained from low-altitude UAS gathering information at the exact time and place firefighters and land managers are interested in. Close proximity, both geographically and operationally, to the end can reduce latency times below what could ever be possible with satellite observation. This paper expands on recent advances in computer vision, photogrammetry, and infrared and color imagery to develop a framework for a next-generation UAS which can assess fire danger and aid firefighters in real time as they observe, contain, or extinguish wildland fires. It also investigates the impact information gained by this

  3. New acoustic techniques for leak detection in fossil fuel plant components

    NASA Astrophysics Data System (ADS)

    Parini, G.; Possa, G.

    Two on-line acoustic monitoring techniques for leak detection in feedwater preheaters and boilers of fossil fuel power plants are presented. The leak detection is based on the acoustic noise produced by the turbulent leak outflow. The primary sensors are piezoelectric pressure transducers, installed near the feedwater preheater inlets, in direct contact with the water, or mounted on boiler observation windows. The frequency band of the auscultation ranges from a few kHz, to 10 to 15 kHz. The signals are characterized by their rms value, continuously recorded by means of potentiometric strip chart recorders. The leak occurrence is signalled by the signal rms overcoming predetermined threshold levels. Sensitivity, reliability, acceptance in plant control practice, and costs-benefits balance are satisfactory.

  4. Swelling behavior detection of irradiated U-10Zr alloy fuel using indirect neutron radiography

    NASA Astrophysics Data System (ADS)

    Sun, Yong; Huo, He-yong; Wu, Yang; Li, Jiangbo; Zhou, Wei; Guo, Hai-bing; Li, Hang; Cao, Chao; Yin, Wei; Wang, Sheng; Liu, Bin; Feng, Qi-jie; Tang, Bin

    2016-11-01

    It is hopeful that fusion-fission hybrid energy system will become an effective approach to achieve long-term sustainable development of fission energy. U-10Zr alloy (which means the mass ratio of Zr is 10%) fuel is the key material of subcritical blanket for fusion-fission hybrid energy system which the irradiation performance need to be considered. Indirect neutron radiography is used to detect the irradiated U-10Zr alloy because of the high residual dose in this paper. Different burnup samples (0.1%, 0.3%, 0.5% and 0.7%) have been tested with a special indirect neutron radiography device at CMRR (China Mianyang Research Reactor). The resolution of the device is better than 50 μm and the quantitative analysis of swelling behaviors was carried out. The results show that the swelling behaviors relate well to burnup character which can be detected accurately by indirect neutron radiography.

  5. Detecting proton exchange membrane fuel cell hydrogen leak using electrochemical impedance spectroscopy method

    NASA Astrophysics Data System (ADS)

    Mousa, Ghassan; Golnaraghi, Farid; DeVaal, Jake; Young, Alan

    2014-01-01

    When a proton exchange membrane (PEM) fuel cell runs short of hydrogen, it suffers from a reverse potential fault that, when driven by neighboring cells, can lead to anode catalyst degradation and holes in the membrane due to local heat generation. As a result, hydrogen leaks through the electrically-shorted membrane-electrode assembly (MEA) without being reacted, and a reduction in fuel cell voltage is noticed. Such voltage reduction can be detected by using electrochemical impedance spectroscopy (EIS). To fully understand the reverse potential fault, the effect of hydrogen crossover leakage in a commercial MEA is measured by EIS at different differential pressures between the anode and cathode. Then the signatures of these leaky cells were compared with the signatures of a no-leaky cells at different oxygen concentrations with the same current densities. The eventual intent of this early stage work is to develop an on-board diagnostics system that can be used to detect and possibly prevent cell reversal failures, and to permit understanding the status of crossover or transfer leaks versus time in operation.

  6. Failing Liberty 101

    ERIC Educational Resources Information Center

    Damon, William

    2012-01-01

    The author presents evidence of "glaring gaps in U.S. students' civic knowledge, motivation, and interest." From the inception of the United States through the mid-20th century, he writes, civic education was at the center of U.S. schooling. Since then, however, there has been a decline in civics instruction, fueled by increasing…

  7. Detecting fossil fuel emissions patterns from subcontinental regions using North American in situ CO2 measurements.

    PubMed

    Shiga, Yoichi P; Michalak, Anna M; Gourdji, Sharon M; Mueller, Kim L; Yadav, Vineet

    2014-06-28

    The ability to monitor fossil fuel carbon dioxide (FFCO2) emissions from subcontinental regions using atmospheric CO2 observations remains an important but unrealized goal. Here we explore a necessary but not sufficient component of this goal, namely, the basic question of the detectability of FFCO2 emissions from subcontinental regions. Detectability is evaluated by examining the degree to which FFCO2 emissions patterns from specific regions are needed to explain the variability observed in high-frequency atmospheric CO2 observations. Analyses using a CO2 monitoring network of 35 continuous measurement towers over North America show that FFCO2 emissions are difficult to detect during nonwinter months. We find that the compounding effects of the seasonality of atmospheric transport patterns and the biospheric CO2 flux signal dramatically hamper the detectability of FFCO2 emissions. Results from several synthetic data case studies highlight the need for advancements in data coverage and transport model accuracy if the goal of atmospheric measurement-based FFCO2 emissions detection and estimation is to be achieved beyond urban scales.

  8. The detection of palladium particles in proton exchange membrane fuel-cell water by laser-induced breakdown spectroscopy (LIBS).

    PubMed

    Snyder, Stuart C; Wickun, William G; Mode, Jeremy M; Gurney, Brian D; Michels, Fred G

    2011-06-01

    Laser-induced breakdown spectroscopy (LIBS) using conditional data analysis was applied to aqueous suspensions of palladium particles in the reformate water of palladium-based proton exchange membrane fuel cells. A significant amount of palladium was found in the water, indicating degradation of the fuel-cell cathode catalytic layers. The palladium particle-size detection limit was found to be about 400 nm. Calibration procedures to quantify the palladium concentration are discussed.

  9. Applicability of grid-net detection system for landfill leachate and diesel fuel release in the subsurface

    NASA Astrophysics Data System (ADS)

    Oh, Myounghak; Seo, Min Woo; Lee, Seunghak; Park, Junboum

    2008-02-01

    The grid-net system estimating the electrical conductivity changes was evaluated as a potential detection system for the leakage of diesel fuel and landfill leachate. Aspects of electrical conductivity changes were varied upon the type of contaminant. The electrical conductivity in the homogeneous mixtures of soil and landfill leachate linearly increased with the ionic concentration of pore fluid, which became more significant at higher volumetric water contents. However, the electrical conductivity in soil/diesel fuel mixture decreased with diesel fuel content and it was more significant at lower water contents. The electrode spacing should be determined by considering the type of contaminant to enhance the electrode sensitivity especially when two-electrode sensors are to be used. The electrode sensitivity for landfill leachate was constantly maintained regardless of the electrode spacings while that for the diesel fuel significantly increased at smaller electrode spacings. This is possibly due to the fact that the insulating barrier effect of the diesel fuel in non-aqueous phase was less predominant at large electrode spacing because electrical current can form the round-about paths over the volume with relatively small diesel fuel content. The model test results showed that the grid-net detection system can be used to monitor the leakage from waste landfill and underground storage tank sites. However, for a successful application of the detection system in the field, data under various field conditions should be accumulated.

  10. Detection and Identification of Sulfur Compounds in an Australian Jet Fuel

    DTIC Science & Technology

    2010-06-01

    Australian Jet Fuel Executive Summary Jet fuel contains a wide range of sulfur compounds that affect the properties and performance of...the fuel in a number of ways, including corrosion of uncoated metals, effects on fuel lubricity, and on both thermal and storage stability properties ...All of these properties are ongoing concerns for the ADF. Jet fuel used by the ADF has its sulfur content controlled through specification DEF(AUST

  11. Development of a simple field test for vehicle exhaust to detect illicit use of dyed diesel fuel.

    PubMed

    Harvey, Scott D; Wright, Bob W

    2011-10-30

    Tax-free diesel fuel is intended for off-road uses such as agricultural operations, but illicit use of this fuel does occur and is a convenient way of evading payment of excise taxes. Current enforcement to prevent this practice involves visual inspection for the red azo dye added to the fuel to indicate its tax-free status. This approach, while very effective, has shortcomings such as the invasive nature of the tests and/or various deceptive tactics applied by tax evaders. A test designed to detect illicit dyed-fuel use by analyzing the vehicle exhaust would circumvent these shortcomings. This paper describes the development of a simple color spot test designed to detect the use of tax-free (i.e., dyed) fuel by analyzing the engine exhaust. Development efforts first investigated the combustion products of C.I. Solvent Red 164 (the azo dye formulation used in the United States to tag tax-free fuel). A variety of aryl amines were identified as characteristic molecular remnants that appear to survive combustion. A number of micro-analytical color tests specific for aryl amines were then investigated. One test that detected aryl amines by reacting with 4-(dimethylamino)benzaldehyde seemed to be particularly applicable and was used in a proof-of-principle experiment. The 4-(dimethylamino)benzaldehyde color spot test was able to clearly distinguish between engines that were burning regular fuel and those that were burning dyed diesel fuel. Further development will refine this color spot test to provide an easy-to-use field test.

  12. Hydrogen uptake in Zircaloy-2 reactor fuel claddings studied with elastic recoil detection

    NASA Astrophysics Data System (ADS)

    Rajasekhara, S.; Doyle, B. L.; Enos, D. G.; Clark, B. G.

    2013-04-01

    The recent trend towards a high burn-up discharge spent nuclear fuel necessitates a thorough understanding of hydrogen uptake in Zr-based cladding materials that encapsulate spent nuclear fuel. Although it is challenging to experimentally replicate exact conditions in a nuclear reactor that lead to hydrogen uptake in claddings, in this study we have attempted to understand the kinetics of hydrogen uptake by first electrolytically charging Zircaloy-2 (Zr-2) cladding material for various durations (100 to 2,600 s), and subsequently examining hydrogen ingress with elastic recoil detection (ERD) and transmission electron microscopy (TEM). To understand the influence of irradiation damage defects on hydrogen uptake, an analogous study was performed on ion - irradiated (0.1, 1 and 25 dpa) Zr-2. Analysis of ERD data from the un-irradiated Zr-2 suggests that the growth of the hydride layer is diffusion controlled, and preliminary TEM results support this assertion. In un-irradiated Zr-2, the diffusivity of hydrogen in the hydride phase was found to be approximately 1.1 × 10-11 cm2/s, while the diffusivity in the hydride phase for lightly irradiated (0.1 and 1 dpa) Zr-2 is an order of magnitude lower. Irradiation to 25 dpa results in a hydrogen diffusivity that is comparable to the un-irradiated Zr-2. These results are compared with existing literature on hydrogen transport in Zr - based materials.

  13. [FTIR detection of unregulated emissions from a diesel engine with biodiesel fuel].

    PubMed

    Tan, Pi-qiang; Hu, Zhi-yuan; Lou, Di-ming

    2012-02-01

    Biodiesel, as one of the most promising alternative fuels, has received more attention because of limited fossil fuels. A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions. A diesel fuel, a pure biodiesel fuel, and fuel with 20% V/V biodiesel blend ratio were tested without engine modification The present study examines six typical unregulated emissions by Fourier transform infrared spectroscopy (FTIR) method: formaldehyde (HCHO), acetaldehyde (C2 H4 O), acetone (C3 H6 O), toluene (C7 H8), sulfur dioxide (SO2), and carbon dioxide (CO2). The results show addition of biodiesel fuel increases the formaldehyde emission, and B20 fuel has little change, but the formaldehyde emission of pure biodiesel shows a clear trend of addition. Compared with the pure diesel fuel, the acetaldehyde of B20 fuel has a distinct decrease, and the acetaldehyde emission of pure biodiesel is lower than that of the pure diesel fuel at low and middle engine loads, but higher at high engine load. The acetone emission is very low, and increases for B20 and pure biodiesel fuels as compared to diesel fuel. Compared with the diesel fuel, the toluene and sulfur dioxide values of the engine show a distinct decrease with biodiesel blend ratio increasing. It is clear that the biodiesel could reduce aromatic compounds and emissions of diesel engines. The carbon dioxide emission of pure biodiesel has a little lower value than diesel, showing that the biodiesel benefits control of greenhouse gas.

  14. System for detecting slag level in a solid fuels gasification reactor

    SciTech Connect

    Mayes, M.D.

    1988-06-14

    In combination, a solid fuels gasification reactor and a system for detecting the level of a slag product in the reactor, the reactor includes a quench chamber having a discharge end that connects into a crusher unit, and the slag product is discharged from the quench chamber into the crusher unit, which reduces the particle size of the slag product. The slag level detector system is described comprising: a housing assembly that includes a fluid inlet port and a seal section, the housing member is positioned adjacent to the quench chamber; a nozzle member that fastens inside the housing assembly, and the nozzle member has an open end that extends into the quench chamber; an elongate rod that defines a pokerod; an electronic controller unit adapted for timing an operation cycle; a first position sensor and second position sensor; a space is defined between the pokerod and nozzle member; and a conduit connects the fluid inlet port into a source of fluid.

  15. Quantitative carbon detector for enhanced detection of molecules in foods, pharmaceuticals, cosmetics, flavors, and fuels.

    PubMed

    Beach, Connor A; Krumm, Christoph; Spanjers, Charles S; Maduskar, Saurabh; Jones, Andrew J; Dauenhauer, Paul J

    2016-03-07

    Analysis of trace compounds, such as pesticides and other contaminants, within consumer products, fuels, and the environment requires quantification of increasingly complex mixtures of difficult-to-quantify compounds. Many compounds of interest are non-volatile and exhibit poor response in current gas chromatography and flame ionization systems. Here we show the reaction of trimethylsilylated chemical analytes to methane using a quantitative carbon detector (QCD; the Polyarc™ reactor) within a gas chromatograph (GC), thereby enabling enhanced detection (up to 10×) of highly functionalized compounds including carbohydrates, acids, drugs, flavorants, and pesticides. Analysis of a complex mixture of compounds shows that the GC-QCD method exhibits faster and more accurate analysis of complex mixtures commonly encountered in everyday products and the environment.

  16. Development of a Simple Field Test for Vehicle Exhaust to Detect Illicit Use of Dyed Diesel Fuel

    SciTech Connect

    Harvey, Scott D.; Wright, Bob W.

    2011-10-30

    The use of tax-free dyed fuel on public highways in the United States provides a convenient way of evading taxes. Current enforcement involves visual inspection for the red azo dye added to the fuel to designate its tax-free status. This approach has shortcomings such as the invasive nature of the tests and/or various deceptive tactics applied by tax evaders. A test designed to detect dyed fuel use by analyzing the exhaust would circumvent these shortcomings. This paper describes the development of a simple color spot test designed to detect the use of tax-free (dyed) diesel fuel by analyzing the engine exhaust. Development first investigated the combustion products of C.I. Solvent Red 164 (the azo dye formulation used in the United States to tag tax-free fuel). A variety of aryl amines were identified as characteristic molecular remnants that appear to survive combustion. A number of microanalytical color tests specific for aryl amines were then investigated. One test based on the use of 4-(dimethylamino)benzaldehyde seemed particularly applicable and was used in a proof-of-principle experiment. The 4-(dimethylamino)benzaldehyde color spot test was able to clearly distinguish between engines burning regular and dyed diesel fuel. Further development will refine this color spot test to provide an easy-to-use field test for Internal Revenue Service Field Compliance specialists.

  17. Detecting recalcitrant organic chemicals in water with microbial fuel cells and artificial neural networks.

    PubMed

    King, Scott T; Sylvander, Marc; Kheperu, Mekhakhem; Racz, LeeAnn; Harper, Willie F

    2014-11-01

    This study integrates artificial neural network (ANN) processing with microbial fuel cell (MFC)-based biosensing in the detection of three organic pollutants: aldicarb, dimethyl-methylphosphonate (DMMP), and bisphenol-A (BPA). Overall, the use of the ANN proved to be more reliable than direct correlations for the determination of both chemical concentration and type. The ANN output matched the appropriate chemical concentration and type for three different concentrations and throughout a wide range of stepwise tests. Additionally, chemicals dissolved in the acetate-based feed medium (FM) were accurately identified by the ANN even though the acetate masked the pollutants' effects on electrical current. The ANN also accurately revealed the identity of chemical mixtures. This study is the first to incorporate ANN modeling with MFC-based biosensing for the detection and quantification of organic pollutants that are not readily biodegradable. Furthermore, this work provides insight into the flexibility of MFC-based biosensing as it pertains to limits of detection and its applicability to scenarios where mixtures of pollutants and unique solvents are involved. This research effort is expected to serve as a guide for future MFC-based biosensing efforts.

  18. Minority HIV-1 resistant variants in recent infection and in patients who failed first-line antiretroviral therapy with no detectable resistance-associated mutations in Thailand.

    PubMed

    Le Nguyen, Hai; Pitakpolrat, Patrawadee; Sirivichayakul, Sunee; Delaugerre, Constance; Ruxrungtham, Kiat

    2012-05-01

    Through the Thai National AIDS Program, approximately 200,000 patients infected with HIV are on antiretroviral (ARV) therapy. Although studies have shown low prevalence of primary HIV-1 resistance transmission in Thailand and in Southeast Asia where subtype CRF01_AE is predominant, minority HIV-1 drug resistance has not been studied. Two groups of patients, whose conventional genotyping results showed no drug resistance-associated mutations, were investigated: 104 homosexual men recently infected with HIV-1, naïve to ARV treatment and 22 first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based failure patients. Pyrosequencing (PSQ) assay was developed to detect and quantify minority Y181C and M184V variants from the patients' plasma samples. The sensitivity of PSQ to detect minority Y181C and M184V variants was approximately 1%. 1/104 (0.5%) and 3/101 (3%) samples were found harboring Y181C and M184V in the group of homosexual men recently infected with HIV-1. In patients with first-line treatment failure, one had a minority M184V mutation (4.5%). The prevalence of Y181C and M184V minority variants in homosexual men recently infected and naïve to treatment was low in Thailand. Systematic monitoring of primary resistance transmission in Thailand and this region is essential to guide whether genotypic resistance test is required prior to commencing the first-line highly active antiretroviral therapy (HAART).

  19. Development of a Safeguards Verification Method and Instrument to Detect Pin Diversion from Pressurized Water Reactor (PWR) Spent Fuel Assemblies

    SciTech Connect

    Ham, Y S; Maldonado, G I; Burdo, J; He, T

    2006-10-10

    A technical safeguards challenge has remained for decades for the IAEA to identify possible diversion of nuclear fuel pins from Light Water Reactor (LWR) spent fuel assemblies. In fact, as modern nuclear power plants are pushed to higher power levels and longer fuel cycles, fuel failures (i.e., ''leakers'') as well as the corresponding fuel assembly repairs (i.e., ''reconstitutions'') are commonplace occurrences within the industry. Fuel vendors have performed hundreds of reconstitutions in the past two decades, thus, an evolved know-how and sophisticated tools exist to disassemble irradiated fuel assemblies and replace damaged pins with dummy stainless steel or other type rods. Various attempts have been made in the past two decades to develop a technology to identify a possible diversion of pin(s) and to determine whether some pins are missing or replaced with dummy or fresh fuel pins. However, to date, there are no safeguards instruments that can detect a possible pin diversion scenario to the requirements of the IAEA. The FORK detector system [1-2] can characterize spent fuel assemblies using operator declared data, but it is not sensitive enough to detect missing pins from spent fuel assemblies. Likewise, an emission computed tomography system [3] has been used to try to detect missing pins from a spent fuel assembly, which has shown some potential for identifying possible missing pins but this capability has not yet been fully demonstrated. The use of such a device in the future would not be envisaged, especially in an inexpensive, easy to handle setting for field applications. In this article, we describe a concept and ongoing research to help develop a new safeguards instrument for the detection of pin diversions in a PWR spent fuel assembly. The proposed instrument is based on one or more very thin radiation detectors that could be inserted within the guide tubes of a Pressurized Water Reactor (PWR) assembly. Ultimately, this work could lead to the

  20. N-[11C]methylspiperone PET, in contrast to [11C]raclopride, fails to detect D2 receptor occupancy by an atypical neuroleptic.

    PubMed

    Hagberg, G; Gefvert, O; Bergström, M; Wieselgren, I M; Lindström, L; Wiesel, F A; Långström, B

    1998-06-30

    The occupancy of the atypical neuroleptic quetiapine (Seroquel) at the D2 dopamine receptor was investigated using the PET tracers [11C]raclopride and N-[11C]methylspiperone in a group of five schizophrenic patients. A steady-state treatment condition was ensured by dosing the patients with 750 mg quetiapine daily during 3 weeks followed by a period of tapering off the dose. For each patient, PET examinations were performed with both tracers at two of the following doses: 750, 450, 300 and/or 150 mg. As control, a group of six healthy untreated volunteers was investigated. The D2 binding potential in the putamen and the caudate nucleus was determined by using an evaluation method based on the method proposed by Patlak and Blasberg. The receptor occupancy was determined by assuming that the group of healthy volunteers is representative of untreated drug-naive schizophrenic patients. While a significant linear trend of increasing occupancy with increasing quetiapine dose (reaching 51% +/- 10% occupancy at the 750 mg dose) was detected with [11C]raclopride (P < 0.01), no such trend was apparent for N-[11C]methylspiperone (P > 0.09, maximal occupancy values were 2% +/- 3%, measured for the group of three patients on 450 mg). The study suggests that N-[11C]methylspiperone cannot be used for the assessment of D2 receptor occupancy induced by quetiapine. The result is discussed in terms of endogenous dopamine, tracer kinetics and equilibrium dissociation constants.

  1. Millimeter Wave Detection of Localized Anomalies in the Space Shuttle External Fuel Tank Insulating Foam

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Case, J. T.; Abou-Khousa, M. A.; Zoughi, R.; Hepburn, F.

    2006-01-01

    The Space Shuttle Columbia's catastrophic accident emphasizes the growing need for developing and applying effective, robust and life-cycle oriented nondestructive testing (NDT) methods for inspecting the shuttle external fuel tank spray on foam insulation (SOFI). Millimeter wave NDT techniques were one of the methods chosen for evaluating their potential for inspecting these structures. Several panels with embedded anomalies (mainly voids) were produced and tested for this purpose. Near-field and far-field millimeter wave NDT methods were used for producing images of the anomalies in these panels. This paper presents the results of an investigation for the purpose of detecting localized anomalies in several SOFI panels. To this end, reflectometers at a relatively wide range of frequencies (Ka-band (26.5 - 40 GHz) to W-band (75 - 110 GHz)) and utilizing different types of radiators were employed. The resulting raw images revealed a significant amount of information about the interior of these panels. However, using simple image processing techniques the results were improved in particular as it relate s to detecting the smaller anomalies. This paper presents the results of this investigation and a discussion of these results.

  2. Detection of androgenic activity in emissions from diesel fuel and biomass combustion.

    PubMed

    Owens, Clyde V; Lambright, Christy; Cardon, Mary; Gray, L Earl; Gullett, Brian K; Wilson, Vickie S

    2006-08-01

    The present study evaluated both diesel fuel exhaust and biomass (wood) burn extracts for androgen receptor-mediated activity using MDA-kb2 cells, which contain an androgen-responsive promoter-luciferase reporter gene construct. This assay and analytical fractionization of the samples were used as tools to separate active from inactive fractions, with the goal of identifying the specific compounds responsible for the activity. A significant androgenic response was detected from the diesel emission. High-performance liquid chromatographic fractionation of the sample indicated that significant androgenic activity was retained in three fractions. 4-Hydroxybiphenyl was identified from the most active fraction using gas chromatography/mass spectroscopy. This purified compound was then tested at doses from 1 nM to 100 microM. 4-Hydroxybiphenol exhibited antagonist activity at low concentrations and agonist activity at high concentrations. A competitive-binding assay confirmed binding to the androgen receptor, with a median inhibitory concentration for radioligand binding of approximately 370 nM. Significant androgenic activity also was detected in the wood burn samples, but we were unable to identify the specific chemicals responsible for this endocrine activity. The present study demonstrates that in vitro bioassays can serve as sensitive bioanalytical tools to aid in characterization of complex environmental mixtures.

  3. Bioelectrocatalysts: engineered oxidoreductase system for utilization of fumarate reductase in chemical synthesis, detection, and fuel cells.

    PubMed

    Park, Doo Hyun; Vieille, C; Zeikus, J G

    2003-10-01

    Fumarate reductase was used as a model oxidoreductase to demonstrate continuous electrical cofactor reduction-oxidation during the bioelectrochemical synthesis and detection of chemicals. The enzyme preparation was immobilized onto a graphite felt electrode that was modified with carboxymethylcellulose (CMC). Nicotinamide adenine dinucleotide (NAD), neutral red, and fumarate reductase (which contained menaquinone) were covalently linked by peptide bonds to the CMC. The electron mediator neutral red allowed NAD and menaquinone to be recycled electrically during enzymatic chemical synthesis. Succinate detection by the bioelectrocatalyst was linear from 5 microM to 10 mM succinate. Fumarate synthesis using this bioelectrode was dependent on succinate utilization and resulted in proportional production of electricity and fumarate. Succinate synthesis using this bioelectrocatalyst was dependent on current and fumarate concentration. This bioelectrocatalyst system may enhance the utility of menaquinone- and/or pyridine nucleotide-linked oxidoreductases in diverse enzymatic fuel cells and sensors. It may also enhance the utility of oxidoreductase-based chemical synthesis systems because it eliminates the problem of cofactor recycling.

  4. Separation and detection of amino acid metabolites of Escherichia coli in microbial fuel cell with CE.

    PubMed

    Wang, Wei; Ma, Lihong; Lin, Ping; Xu, Kaixuan

    2016-07-01

    In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L.

  5. When Fundoplication Fails

    PubMed Central

    Smith, C Daniel; McClusky, David A.; Rajad, Murad Abu; Lederman, Andrew B.; Hunter, John G.

    2005-01-01

    Objective: The largest series in the literature dealing with redo fundoplication was presented and published in 1999 and included 100 patients. Herein we update this initial series of 100, with 207 additional patients who have undergone redo fundoplication (n = 307). Summary Background Data: Increasing numbers of patients are failing esophagogastric fundoplication and requiring redo procedures. Data regarding the nature of these failures have been scant. Methods: Data on all patients undergoing foregut surgery are collected prospectively. Between 1991 and 2004, 307 patients underwent redo fundoplication for the management of anatomic complications or recurrent GERD. Statistical analysis was performed with multiple χ2 and Mann-Whitney U analyses, as well as ANOVA. Results: Between 1991 and 2004, 1892 patients underwent primary fundoplication for GERD (1734) or paraesophageal hernia (158). Of these, 54 required redo fundoplication (2.8%). The majority of failures (73%) were managed within 2 years of the initial operation (P = 0.0001). The mechanism of failure was transdiaphragmatic wrap herniation in 33 of 54 (61%). In the 231 patients who underwent fundoplication elsewhere, 109 had transdiaphragmatic herniation (47%, P = NS). In this group of 285 patients, 22 (8%) required another redo (P = NS). The majority of the procedures were initiated laparoscopically (240/307, 78%), with 20 converted (8%). Overall mortality was 0.3%. Conclusions: Failure of fundoplication is unusual in experienced hands. Most are managed within 2 years of the initial operation. Wrap herniation has now become the most common mechanism of failure requiring redo. Redo fundoplication was successful in 93% of patients, and most could be safely handled laparoscopically. PMID:15912035

  6. An investigation towards real time dose rate monitoring, and fuel rod detection in a First Generation Magnox Storage Pond (FGMSP).

    PubMed

    Jackson, Sarah F; Monk, Stephen D; Riaz, Zahid

    2014-12-01

    The First Generation Magnox Storage Pond (FGMSP) is located on the Sellafield Nuclear Site, housing legacy spent Magnox nuclear fuel. Some of which has since corroded, forming a layer of Corroded Magnox Sludge (CMS) creating one of the largest decommissioning challenges the UK has faced. In this work the composition, physical properties and potentially high hazard nature of CMS are discussed, as are the gamma emission spectra of spent Magnox fuel rods typical of the ilk stored. We assess the potential use of a RadLine gamma detector to dose rate map this area and provide fuel rod detection. RadLine consists of a small scintillator, fibre optic cable and photon counter. The probe has the unusual advantage of not being electrically active and therefore fully submersible underwater, with the option to deploy hundreds of metres in length. Our experimental method encompasses general purpose Monte Carlo radiation transport code, MCNP, where we describe the modelling of CMS and pond liquor in comprehensive detail, including their radiological spectrum, chemical composition data, and physical properties. This investigation concludes that the maximum energy deposited within the scintillator crystal due to ambient CMS corresponds to a dose rate of 5.65Gy h(-1), thus above this value positive detection of a fuel rod would be anticipated. It is additionally established that the detectable region is within a 20cm range.

  7. Diffuse neutrino flux from failed supernovae.

    PubMed

    Lunardini, Cecilia

    2009-06-12

    I study the diffuse flux of electron antineutrinos from stellar collapses with direct black hole formation (failed supernovae). This flux is more energetic than that from successful supernovae, and therefore it might contribute substantially to the total diffuse flux above realistic detection thresholds. The total flux might be considerably higher than previously thought, and approach the sensitivity of Super-Kamiokande. For more conservative values of the parameters, the flux from failed supernovae dominates for antineutrino energies above 30-45 MeV, with potential to give an observable spectral distortion at megaton detectors.

  8. Applicability of a submersible microbial fuel cell for Cr(VI) detection in water.

    PubMed

    Chung, Hyeonyong; Ju, Won Jung; Jho, Eun Hea; Nam, Kyoungphile

    2016-11-01

    Two-chamber microbial fuel cells (MFCs) were used to study the applicability of MFCs for hexavalent chromium (Cr(VI)) detection in water. The microbial acetate oxidation in the anode and the Cr(VI) reduction in the cathode together generated voltages, which were used to indicate the change in Cr(VI) concentrations of the cathode under varying conditions of pH, ionic strength, co-existing Fe(II) concentration, and organic matter concentration. The MFC-based Cr(VI) detector showed a significant change in voltage with increasing Cr(VI) concentration at pH 1 and 2, but not at higher pH conditions. The detector also successfully measured the changes in Cr(VI) concentration at a range of ionic strength (i.e., 10-300 mM), and in the presence of different concentrations of fulvic acid (0-50 mg/L), which was used as a surrogate of organic matters, without interference. The Cr(VI) detection was not interfered by the presence of Fe(II) at the Cr(VI)/Fe(II) ratio of 1:1 and 1:15, but it was interfered at higher ratios (i.e., 1:164 and 1:848). The detector could measure the Cr(VI) concentration from 0.1 to 15 mg/L at pH 2. Overall, the MFC-based Cr(VI) detector may be applied to meet the growing need of real-time Cr(VI) monitoring in water.

  9. Navy Field Evaluation of Particle Counter Technology for Aviation Fuel Contamination Detection

    DTIC Science & Technology

    2014-02-06

    In addition, free water can potentially freeze and clog fuel lines and fuel pumps. The presence of free water can also facilitate the formation of...4 3.4 FREE WATER AND SEDIMENT ANALYSIS...0 ppm Free Water as Determined by ASTM Methods .................................................................................................10

  10. Can Failing Schools Be Fixed?

    ERIC Educational Resources Information Center

    Brady, Ronald C.

    2003-01-01

    The No Child Left Behind Act of 2001 (NCLB) requires states and school districts to act aggressively to turn around failing schools. NCLB lists 31 different interventions of varying degrees of severity that are available to state and local policymakers when faced with schools whose students fail to make sufficient academic progress and sets forth…

  11. Mitochondrial protein hyperacetylation in the failing heart

    PubMed Central

    Horton, Julie L.; Martin, Ola J.; Lai, Ling; Richards, Alicia L.; Vega, Rick B.; Leone, Teresa C.; Pagliarini, David J.; Muoio, Deborah M.; Bedi, Kenneth C.; Coon, Joshua J.

    2016-01-01

    Myocardial fuel and energy metabolic derangements contribute to the pathogenesis of heart failure. Recent evidence implicates posttranslational mechanisms in the energy metabolic disturbances that contribute to the pathogenesis of heart failure. We hypothesized that accumulation of metabolite intermediates of fuel oxidation pathways drives posttranslational modifications of mitochondrial proteins during the development of heart failure. Myocardial acetylproteomics demonstrated extensive mitochondrial protein lysine hyperacetylation in the early stages of heart failure in well-defined mouse models and the in end-stage failing human heart. To determine the functional impact of increased mitochondrial protein acetylation, we focused on succinate dehydrogenase A (SDHA), a critical component of both the tricarboxylic acid (TCA) cycle and respiratory complex II. An acetyl-mimetic mutation targeting an SDHA lysine residue shown to be hyperacetylated in the failing human heart reduced catalytic function and reduced complex II–driven respiration. These results identify alterations in mitochondrial acetyl-CoA homeostasis as a potential driver of the development of energy metabolic derangements that contribute to heart failure. PMID:26998524

  12. Failed detection of Bovine viral diarrhea virus 2 subgenotype a (BVDV-2a) by direct fluorescent antibody test on tissue samples due to reduced reactivity of field isolates to raw anti-BVDV antibody.

    PubMed

    Yan, Lifang; Pace, Lanny W; Baughman, Brittany; Wilson, Floyd D; Zhang, Shuping; Zhang, Michael Z

    2016-03-01

    Bovine viral diarrhea virus 1 (BVDV-1) is associated with mild or subclinical infections, whereas BVDV-2 is frequently implicated in outbreaks of severe thrombocytopenia and acute fatal disease. In the present study, the carcass of a beef breed cow and tissue samples of a beef calf were received for laboratory diagnosis. Both animals exhibited severe clinical signs compatible with thrombocytopenia or hemorrhagic syndrome. Direct fluorescent antibody test (DFAT) failed to detect BVDV antigen in the tissue specimens of both cases. However, immunohistochemistry (IHC) revealed the presence of BVDV antigen in oral and esophageal mucosa and Peyer patches of the beef breed cow. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) detected BVDV-2 in selected tissues of both animals. Subsequently, BVDV was isolated from both cases and subjected to genetic and serologic characterizations. Mutations in the 5'-untranslated genomic region (5'-UTR) primer and probe binding sites and the E2 gene were associated with reduced efficiency of an established real-time RT-PCR assay and amino acid alterations in the E2 glycoprotein, respectively. Both viral isolates were classified by real-time RT-PCR and phylogenetic analysis as BVDV-2 subgenotype a. Unlike BVDV reference strains Singer and 125c, the isolates cross-reacted with anti-BVDV-1 and anti-BVDV-2 reference sera, indicating antigenic variations in field isolates. The isolates also showed reduced reactivity to porcine anti-BVDV antiserum (the raw serum used to produce BVDV DFA conjugate). In summary, data from the present investigation indicated that genetic and antigenic variations affected the performance of detection assays, especially DFAT, highlighting the need for regular evaluation and modification of BVDV tests.

  13. Interaction of cosmic ray muons with spent nuclear fuel dry casks and determination of lower detection limit

    NASA Astrophysics Data System (ADS)

    Chatzidakis, S.; Choi, C. K.; Tsoukalas, L. H.

    2016-08-01

    The potential non-proliferation monitoring of spent nuclear fuel sealed in dry casks interacting continuously with the naturally generated cosmic ray muons is investigated. Treatments on the muon RMS scattering angle by Moliere, Rossi-Greisen, Highland and, Lynch-Dahl were analyzed and compared with simplified Monte Carlo simulations. The Lynch-Dahl expression has the lowest error and appears to be appropriate when performing conceptual calculations for high-Z, thick targets such as dry casks. The GEANT4 Monte Carlo code was used to simulate dry casks with various fuel loadings and scattering variance estimates for each case were obtained. The scattering variance estimation was shown to be unbiased and using Chebyshev's inequality, it was found that 106 muons will provide estimates of the scattering variances that are within 1% of the true value at a 99% confidence level. These estimates were used as reference values to calculate scattering distributions and evaluate the asymptotic behavior for small variations on fuel loading. It is shown that the scattering distributions between a fully loaded dry cask and one with a fuel assembly missing initially overlap significantly but their distance eventually increases with increasing number of muons. One missing fuel assembly can be distinguished from a fully loaded cask with a small overlapping between the distributions which is the case of 100,000 muons. This indicates that the removal of a standard fuel assembly can be identified using muons providing that enough muons are collected. A Bayesian algorithm was developed to classify dry casks and provide a decision rule that minimizes the risk of making an incorrect decision. The algorithm performance was evaluated and the lower detection limit was determined.

  14. Fault detection and isolation of PEM fuel cell system based on nonlinear analytical redundancy. An application via parity space approach

    NASA Astrophysics Data System (ADS)

    Aitouche, A.; Yang, Q.; Ould Bouamama, B.

    2011-05-01

    This paper presents a procedure dealing with the issue of fault detection and isolation (FDI) using nonlinear analytical redundancy (NLAR) technique applied in a proton exchange membrane (PEM) fuel cell system based on its mathematic model. The model is proposed and simplified into a five orders state space representation. The transient phenomena captured in the model include the compressor dynamics, the flow characteristics, mass and energy conservation and manifold fluidic mechanics. Nonlinear analytical residuals are generated based on the elimination of the unknown variables of the system by an extended parity space approach to detect and isolate actuator and sensor faults. Finally, numerical simulation results are given corresponding to a faults signature matrix.

  15. Detecting and localizing failure points in proton exchange membrane fuel cells using IR thermography

    NASA Astrophysics Data System (ADS)

    Bender, Guido; Felt, Wyatt; Ulsh, Michael

    2014-05-01

    An understanding of the potentially serious long-term performance degradation effects that coating and/or other fabrication irregularities might have in mass produced proton exchange membrane fuel cells (PEMFC) is essential to determine manufacturing tolerances of fuel cell components. An experimental setup and methodology is described that employs accelerated stress tests (ASTs) and IR thermography to accurately determine the location and severity of developing failure points in PEMFCs. The method entails a novel hardware that allows the spatial observation of a hydrogen crossover experiment within a fuel cell hardware. The application of the method is demonstrated by comparing the effects of an AST on pristine as well as defect-containing MEAs. The presented method is shown to be valuable for determining the areas within a fuel cell that are most stressed by aging processes.

  16. Detection of water in jet fuel using layer-by-layer thin film coated long period grating sensor.

    PubMed

    Puckett, Sean D; Pacey, Gilbert E

    2009-04-15

    The quantitative measurement of jet fuel additives in the field is of interest to the Air Force. The "smart nozzle" project was designed as a state-of-the-art diagnostics package attached to a single-point refueling nozzle for assessing key fuel properties as the fuel is dispensed. The objective of the work was to show proof of concept that a layer-by-layer thin film and long period grating fibers could be used to detect the presence of water in jet fuel. The data for the nafion/PDMA film and a long period grating fiber is a combination capable of quantitative measurement of water in kerosene. The average response (spectral loss wavelength shift) to the kerosene sample ranged from -6.0 for 15 ppm to -126.5 for 60 ppm water. The average calculated value for the check standard was 21.71 and ranged from 21.25 to 22.00 with a true value of 22.5 ppm water. Potential interferences were observed and are judged to be insignificant in real samples.

  17. In-line deoxygenation for organic carbon detections in seawater using a marine microbial fuel cell-biosensor.

    PubMed

    Quek, Soon Bee; Cheng, Liang; Cord-Ruwisch, Ralf

    2015-04-01

    Assimilable organic carbon (AOC) is a key predictor for membrane biofouling in seawater desalination reverse osmosis (SWRO). Microbial fuel cells have been considered as biosensors for the detection of biodegradable organics. However, the presence of dissolved oxygen (DO) is known to completely suppress the signal production (i.e., current) of a typical MFC. This study describes AOC detection in normal oxygenated seawater by coupling an electrochemical cell for DO removal with a MFC-biosensor for AOC detection. The electrochemical deoxygenation for oxygen removal caused no interference in the AOC detection. A linear relationship (R(2)=0.991) between the AOC concentration and current production from the MFC biosensor was achieved. The coupling of an electrochemical cell with a MFC-biosensor can be effectively used as an online, rapid and inexpensive measure of AOC concentrations and hence as an indicator for biofouling potential of seawater.

  18. Evaluation of Particle Counter Technology for Detection of Fuel Contamination Detection Utilizing Advanced Aviation Forward Area Refueling System

    DTIC Science & Technology

    2014-01-24

    replacement of water bottom removal.  Recirculation – Air was purged from the filter separator vessel and fuel was again pumped from the tank , through...8, Automatic Particle Counter, cleanliness, free water , Diesel 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT none 18. NUMBER OF...Advanced Aviation Forward Area Refueling System Joel Schmitigal U S Army Tank Automotive Research DISTRIBUTION STATEMENT A. Approved for public release

  19. Method to improve reliability of a fuel cell system using low performance cell detection at low power operation

    DOEpatents

    Choi, Tayoung; Ganapathy, Sriram; Jung, Jaehak; Savage, David R.; Lakshmanan, Balasubramanian; Vecasey, Pamela M.

    2013-04-16

    A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage is greater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

  20. Water vapour emission in vegetable fuel: absorption cell measurements and detection limits of our CO II Dial system

    NASA Astrophysics Data System (ADS)

    Bellecci, C.; De Leo, L.; Gaudio, P.; Gelfusa, M.; Lo Feudo, T.; Martellucci, S.; Richetta, M.

    2006-09-01

    Forest fires can be the cause of serious environmental and economic damages. For this reason a considerable effort has been directed toward the forest protection and fire fighting. In the early forest fire detection, Lidar technique present considerable advantages compared to the passive detection methods based on infrared cameras currently in common use, due its higher sensitivity and ability to accurately locate the fire. The combustion phase of the vegetable matter causes a great amount of water vapour emission, thus the water molecule behaviour will be studied to obtain a fire detection system ready and efficient also before the flame propagation. A first evaluation of increment of the water vapour concentration compared to standard one will be estimated by a numerical simulation. These results will be compared with the experimental measurements carried out into a cell with a CO II Dial system, burning different kinds of vegetable fuel. Our results and their comparison will be reported in this paper.

  1. Detecting Solenoid Valve Deterioration in In-Use Electronic Diesel Fuel Injection Control Systems

    PubMed Central

    Tsai, Hsun-Heng; Tseng, Chyuan-Yow

    2010-01-01

    The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT) sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves. PMID:22163597

  2. DETECTION OF ANDROGENIC ACTIVITY IN EMISSIONS FROM DIESEL FUEL AND BIOMASS COMBUSTION

    EPA Science Inventory

    The present study evaluated both diesel fuel exhaust and biomass (wood) burn extracts for androgen receptor¿mediated activity using MDA-kb2 cells, which contain an androgen-responsive promoter-luciferase reporter gene construct. This assay and analytical fractionization of the sa...

  3. Detecting solenoid valve deterioration in in-use electronic diesel fuel injection control systems.

    PubMed

    Tsai, Hsun-Heng; Tseng, Chyuan-Yow

    2010-01-01

    The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT) sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves.

  4. Field Evaluation of Particle Counter Technology for Aviation Fuel Contamination Detection - Fort Campbell

    DTIC Science & Technology

    2013-06-06

    fibrous materials, coatings material including paint, elastomeric materials, hydrocarbon/oxidation materials, and any other solid matter. At a...storage volume for CAA to 1.3M gallons. The fuel offloaded is not filtered prior to storage. JP-8 is transferred via a 0.5 mile underground pipeline

  5. Helium Leak Detection of Vessels in Fuel Transfer Cell (FTC) of Prototype Fast Breeder Reactor (PFBR)

    NASA Astrophysics Data System (ADS)

    Dutta, N. G.

    2012-11-01

    Bharatiya Nabhikiya Vidyut Nigam (BHAVINI) is engaged in construction of 500MW Prototype Fast Breeder Reactor (PFBR) at Kalpak am, Chennai. In this very important and prestigious national programme Special Product Division (SPD) of M/s Kay Bouvet Engg.pvt. ltd. (M/s KBEPL) Satara is contributing in a major way by supplying many important sub-assemblies like- Under Water trolley (UWT), Airlocks (PAL, EAL) Container and Storage Rack (CSR) Vessels in Fuel Transfer Cell (FTC) etc for PFBR. SPD of KBEPL caters to the requirements of Government departments like - Department of Atomic Energy (DAE), BARC, Defense, and Government undertakings like NPCIL, BHAVINI, BHEL etc. and other precision Heavy Engg. Industries. SPD is equipped with large size Horizontal Boring Machines, Vertical Boring Machines, Planno milling, Vertical Turret Lathe (VTL) & Radial drilling Machine, different types of welding machines etc. PFBR is 500 MWE sodium cooled pool type reactor in which energy is produced by fissions of mixed oxides of Uranium and Plutonium pellets by fast neutrons and it also breeds uranium by conversion of thorium, put along with fuel rod in the reactor. In the long run, the breeder reactor produces more fuel then it consumes. India has taken the lead to go ahead with Fast Breeder Reactor Programme to produce electricity primarily because India has large reserve of Thorium. To use Thorium as further fuel in future, thorium has to be converted in Uranium by PFBR Technology.

  6. Infrared Flash Thermography Applied to the External Defect Detection on Htr Fuel Particles during the Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Hermosilla-Lara, S.; Piriou, M.; Levesque, P.

    2008-02-01

    The authors propose the use of an adapted flash thermography method to perform the online detection of open cracks on high temperature reactor (HTR) fuel. The method consists, via an infrared camera, in the measurement of the particle temperature increase produced by a heating pulse on the particle external surface. Study is performed on laser notches and real cracks located in the different particle layers. It includes the influence of the defect relative position with respect to the heating source, as well as the influence of operating conditions. It is shown that this technique is able to yield good discrimination between sound and flawed particles at a rate that meets production constraints.

  7. Making processing fail-safe

    SciTech Connect

    Freiburghouse, R.

    1982-05-01

    The author describes the Stratus/32 multiprocessor, a fault-tolerant system for commercial applications which supports on-line transaction processing, batch processing, word processing and interactive program development. It uses a combination of hardware and software that provides continuous processing of user programs during computer failure without checkpoint/restart programming at the user or system level. Central to the system's fail-safe operation are processing modules, each of which has redundant logic and communication paths, logic and CPU boards and main and disk memory. Twin components operate in parallel with each other; when one fails, its partner carries on.

  8. Development of a Safeguards Verification Method and Instrument to Detect Pin Diversion from Pressurized Water Reactor (PWR) Spent Fuel Assemblies Phase I Study

    SciTech Connect

    Ham, Y S; Sitaraman, S

    2008-12-24

    A novel methodology to detect diversion of spent fuel from Pressurized Water Reactors (PWR) has been developed in order to address a long unsolved safeguards verification problem for international safeguards community such as International Atomic Energy Agency (IAEA) or European Atomic Energy Community (EURATOM). The concept involves inserting tiny neutron and gamma detectors into the guide tubes of a spent fuel assembly and measuring the signals. The guide tubes form a quadrant symmetric pattern in the various PWR fuel product lines and the neutron and gamma signals from these various locations are processed to obtain a unique signature for an undisturbed fuel assembly. Signatures based on the neutron and gamma signals individually or in a combination can be developed. Removal of fuel pins from the assembly will cause the signatures to be visibly perturbed thus enabling the detection of diversion. All of the required signal processing to obtain signatures can be performed on standard laptop computers. Monte Carlo simulation studies and a set of controlled experiments with actual commercial PWR spent fuel assemblies were performed and validated this novel methodology. Based on the simulation studies and benchmarking measurements, the methodology developed promises to be a powerful and practical way to detect partial defects that constitute 10% or more of the total active fuel pins. This far exceeds the detection threshold of 50% missing pins from a spent fuel assembly, a threshold defined by the IAEA Safeguards Criteria. The methodology does not rely on any operator provided data like burnup or cooling time and does not require movement of the fuel assembly from the storage rack in the spent fuel pool. A concept was developed to build a practical field device, Partial Defect Detector (PDET), which will be completely portable and will use standard radiation measuring devices already in use at the IAEA. The use of the device will not require any information provided

  9. Evaluation of a Method for Remote Detection of Fuel Relocation Outside the Original Core Volumes of Fukushima Reactor Units 1-3

    SciTech Connect

    Douglas W. Akers; Edwin A. Harvego

    2012-08-01

    This paper presents the results of a study to evaluate the feasibility of remotely detecting and quantifying fuel relocation from the core to the lower head, and to regions outside the reactor vessel primary containment of the Fukushima 1-3 reactors. The goals of this study were to determine measurement conditions and requirements, and to perform initial radiation transport sensitivity analyses for several potential measurement locations inside the reactor building. The radiation transport sensitivity analyses were performed based on reactor design information for boiling water reactors (BWRs) similar to the Fukushima reactors, ORIGEN2 analyses of 3-cycle BWR fuel inventories, and data on previously molten fuel characteristics from TMI- 2. A 100 kg mass of previously molten fuel material located on the lower head of the reactor vessel was chosen as a fuel interrogation sensitivity target. Two measurement locations were chosen for the transport analyses, one inside the drywell and one outside the concrete biological shield surrounding the drywell. Results of these initial radiation transport analyses indicate that the 100 kg of previously molten fuel material may be detectable at the measurement location inside the drywell, but that it is highly unlikely that any amount of fuel material inside the RPV will be detectable from a location outside the concrete biological shield surrounding the drywell. Three additional fuel relocation scenarios were also analyzed to assess detection sensitivity for varying amount of relocated material in the lower head of the reactor vessel, in the control rods perpendicular to the detector system, and on the lower head of the drywell. Results of these analyses along with an assessment of background radiation effects and a discussion of measurement issues, such as the detector/collimator design, are included in the paper.

  10. Stellar Death by Weak or Failed Supernovae

    NASA Astrophysics Data System (ADS)

    Adams, Scott Michael

    Core collapse supernovae (SNe) - the violent deaths of massive stars - are among the most luminous events in the Universe and play an important role in galaxy evolution and the production and distribution of the heavy elements necessary for planet formation and life. Despite decades of effort it is still unclear how these SNe explode. While SNe have been identified with close to the maximum theoretically possible energies, the lower bounds on SN energies and luminosities are less well-constrained. There is also no requirement that the core collapse always results in a successful SN explosion. In fact, there are multiple lines of evidence that suggest that 10 - 30% of core collapses might result in failed SNe, forming a black hole without a dramatic external explosion. The primary focus of this dissertation is to explore the lower bounds of the possible explosion energies and luminosities of core-collapse SNe. I discuss three observational strategies to help understand how massive stars die. Due to the development of advanced facilities for the detection of neutrinos and gravitational waves, the next Galactic SN will offer an unprecedented opportunity to study the SN explosion mechanism. To aid preparations for this event, I model the distance, extinction, and magnitude probability distributions for a Galactic SN, its shock breakout radiation, and progenitor. I also analyze the archetypes of two types of SN "impostors" and show that they may be genuine SNe, but with energies lower than previously observed. I present results from an ambitious survey that has been monitoring a million massive stars for 7 years to search for failed SNe. I follow-up the first identified failed SN candidate and find that the massive stellar progenitor appears to have vanished leaving behind a faint, fading IR source that may be due to fallback accretion onto a newly formed black hole. Finally, I set new constraints on the fraction of core collapses that result in failed SNe.

  11. Simulating fail-stop in asynchronous distributed systems

    NASA Technical Reports Server (NTRS)

    Sabel, Laura; Marzullo, Keith

    1994-01-01

    The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

  12. Segmented Coil Fails In Steps

    NASA Technical Reports Server (NTRS)

    Stedman, Ronald S.

    1990-01-01

    Electromagnetic coil degrades in steps when faults occur, continues to operate at reduced level instead of failing catastrophically. Made in segments connected in series and separated by electrically insulating barriers. Fault does not damage adjacent components or create hazard. Used to control valves in such critical applications as cooling systems of power generators and chemical process equipment, where flammable liquids or gases handled. Also adapts to electrical control of motors.

  13. Interpretation of high-resolution imagery for detecting vegetation cover composition change after fuels reduction treatments in woodlands

    USGS Publications Warehouse

    Karl, Jason W.; Gillan, Jeffrey K.; Barger, Nichole N.; Herrick, Jeffrey E.; Duniway, Michael C.

    2014-01-01

    The use of very high resolution (VHR; ground sampling distances < ∼5 cm) aerial imagery to estimate site vegetation cover and to detect changes from management has been well documented. However, as the purpose of monitoring is to document change over time, the ability to detect changes from imagery at the same or better level of accuracy and precision as those measured in situ must be assessed for image-based techniques to become reliable tools for ecosystem monitoring. Our objective with this study was to quantify the relationship between field-measured and image-interpreted changes in vegetation and ground cover measured one year apart in a Piñon and Juniper (P–J) woodland in southern Utah, USA. The study area was subject to a variety of fuel removal treatments between 2009 and 2010. We measured changes in plant community composition and ground cover along transects in a control area and three different treatments prior to and following P–J removal. We compared these measurements to vegetation composition and change based on photo-interpretation of ∼4 cm ground sampling distance imagery along similar transects. Estimates of cover were similar between field-based and image-interpreted methods in 2009 and 2010 for woody vegetation, no vegetation, herbaceous vegetation, and litter (including woody litter). Image-interpretation slightly overestimated cover for woody vegetation and no-vegetation classes (average difference between methods of 1.34% and 5.85%) and tended to underestimate cover for herbaceous vegetation and litter (average difference of −5.18% and 0.27%), but the differences were significant only for litter cover in 2009. Level of agreement between the field-measurements and image-interpretation was good for woody vegetation and no-vegetation classes (r between 0.47 and 0.89), but generally poorer for herbaceous vegetation and litter (r between 0.18 and 0.81) likely due to differences in image quality by year and the difficulty in

  14. Fuel flexible fuel injector

    DOEpatents

    Tuthill, Richard S; Davis, Dustin W; Dai, Zhongtao

    2015-02-03

    A disclosed fuel injector provides mixing of fuel with airflow by surrounding a swirled fuel flow with first and second swirled airflows that ensures mixing prior to or upon entering the combustion chamber. Fuel tubes produce a central fuel flow along with a central airflow through a plurality of openings to generate the high velocity fuel/air mixture along the axis of the fuel injector in addition to the swirled fuel/air mixture.

  15. Detection of hydrogen gas-producing anaerobes in refuse-derived fuel (RDF) pellets.

    PubMed

    Sakka, Makiko; Kimura, Tetsuya; Ohmiya, Kunio; Sakka, Kazuo

    2005-11-01

    Recently, we reported that refuse-derived fuel (RDF) pellets contain a relatively high number of viable bacterial cells and that these bacteria generate heat and hydrogen gas during fermentation under wet conditions. In this study we analyzed bacterial cell numbers of RDF samples manufactured with different concentrations of calcium hydroxide, which is usually added to waste materials for the prevention of rotting of food wastes and the acceleration of drying of solid wastes, and determined the amount of hydrogen gas produced by them under wet conditions. Furthermore, we analyzed microflora of the RDF samples before and during fermentation by denaturing gradient gel electrophoresis of 16S rDNA followed by sequencing. We found that the RDF samples contained various kinds of clostridia capable of producing hydrogen gas.

  16. Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

    SciTech Connect

    Ulsh, Michael; Porter, Jason M.; Bittinat, Daniel C.; Bender, Guido

    2016-04-01

    Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDE containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.

  17. Reactive impinging-flow technique for polymer-electrolyte-fuel-cell electrode-defect detection

    DOE PAGES

    Zenyuk, Iryna V.; Englund, Nicholas; Bender, Guido; ...

    2016-09-29

    Reactive impinging flow (RIF) is a novel quality-control method for defect detection (i.e., reduction in Pt catalyst loading) in gas-diffusion electrodes (GDEs) on weblines. The technique uses infrared thermography to detect temperature of a nonflammable (<4% H2) reactive mixture of H2/O2 in N2 impinging and reacting on a Pt catalytic surface. In this article, different GDE size defects (with catalyst-loading reductions of 25, 50, and 100%) are detected at various webline speeds (3.048 and 9.144 m min-1) and gas flowrates (32.5 or 50 standard L min-1). Furthermore, a model is developed and validated for the technique, and it is subsequentlymore » used to optimize operating conditions and explore the applicability of the technique to a range of defects. The model suggests that increased detection can be achieved by recting more of the impinging H2, which can be accomplished by placing blocking substrates on the top, bottom, or both of the GDE; placing a substrate on both results in a factor of four increase in the temperature differential, which is needed for smaller defect detection. Lastly, overall, the RIF technique is shown to be a promising route for in-line, high-speed, large-area detection of GDE defects on moving weblines.« less

  18. Reactive impinging-flow technique for polymer-electrolyte-fuel-cell electrode-defect detection

    NASA Astrophysics Data System (ADS)

    Zenyuk, Iryna V.; Englund, Nicholas; Bender, Guido; Weber, Adam Z.; Ulsh, Michael

    2016-11-01

    Reactive impinging flow (RIF) is a novel quality-control method for defect detection (i.e., reduction in Pt catalyst loading) in gas-diffusion electrodes (GDEs) on weblines. The technique uses infrared thermography to detect temperature of a nonflammable (<4% H2) reactive mixture of H2/O2 in N2 impinging and reacting on a Pt catalytic surface. In this paper, different GDE size defects (with catalyst-loading reductions of 25, 50, and 100%) are detected at various webline speeds (3.048 and 9.144 m min-1) and gas flowrates (32.5 or 50 standard L min-1). Furthermore, a model is developed and validated for the technique, and it is subsequently used to optimize operating conditions and explore the applicability of the technique to a range of defects. The model suggests that increased detection can be achieved by recting more of the impinging H2, which can be accomplished by placing blocking substrates on the top, bottom, or both of the GDE; placing a substrate on both results in a factor of four increase in the temperature differential, which is needed for smaller defect detection. Overall, the RIF technique is shown to be a promising route for in-line, high-speed, large-area detection of GDE defects on moving weblines.

  19. Reactive impinging-flow technique for polymer-electrolyte-fuel-cell electrode-defect detection

    SciTech Connect

    Zenyuk, Iryna V.; Englund, Nicholas; Bender, Guido; Weber, Adam Z.; Ulsh, Michael

    2016-09-29

    Reactive impinging flow (RIF) is a novel quality-control method for defect detection (i.e., reduction in Pt catalyst loading) in gas-diffusion electrodes (GDEs) on weblines. The technique uses infrared thermography to detect temperature of a nonflammable (<4% H2) reactive mixture of H2/O2 in N2 impinging and reacting on a Pt catalytic surface. In this article, different GDE size defects (with catalyst-loading reductions of 25, 50, and 100%) are detected at various webline speeds (3.048 and 9.144 m min-1) and gas flowrates (32.5 or 50 standard L min-1). Furthermore, a model is developed and validated for the technique, and it is subsequently used to optimize operating conditions and explore the applicability of the technique to a range of defects. The model suggests that increased detection can be achieved by recting more of the impinging H2, which can be accomplished by placing blocking substrates on the top, bottom, or both of the GDE; placing a substrate on both results in a factor of four increase in the temperature differential, which is needed for smaller defect detection. Lastly, overall, the RIF technique is shown to be a promising route for in-line, high-speed, large-area detection of GDE defects on moving weblines.

  20. 33 CFR 183.524 - Fuel pumps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel pumps. 183.524 Section...

  1. 33 CFR 183.524 - Fuel pumps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Fuel pumps. 183.524 Section...

  2. 33 CFR 183.524 - Fuel pumps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Fuel pumps. 183.524 Section...

  3. 33 CFR 183.524 - Fuel pumps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Fuel pumps. 183.524 Section...

  4. 33 CFR 183.524 - Fuel pumps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Fuel pumps. 183.524 Section...

  5. Method for detection of trace metal and metalloid contaminants in coal-generated fuel gas using gas chromatography/ion trap mass spectrometry.

    PubMed

    Rupp, Erik C; Granite, Evan J; Stanko, Dennis C

    2010-07-15

    There exists an increasing need to develop a reliable method to detect trace contaminants in fuel gas derived from coal gasification. While Hg is subject to current and future regulations, As, Se, and P emissions may eventually be regulated. Sorbents are the most promising technology for the removal of contaminants from coal-derived fuel gas, and it will be important to develop a rapid analytical detection method to ensure complete removal and determine the ideal time for sorbent replacement/regeneration in order to reduce costs. This technical note explores the use of a commercial gas chromatography/ion trap mass spectrometry system for the detection of four gaseous trace contaminants in a simulated fuel gas. Quantitative, repeatable detection with limits at ppbv to ppmv levels were obtained for arsine (AsH(3)), phosphine (PH(3)), and hydrogen selenide (H(2)Se), while qualitative detection was observed for mercury. Decreased accuracy and response caused by the primary components of fuel gas were observed.

  6. Method for Detection of Trace Metal and Metalloid Contaminants in Coal-Generated Fuel Gas Using Gas Chromatography/Ion Trap Mass Spectrometry

    SciTech Connect

    Rupp, Erik C.; Granite, Evan J.; Stanko, Dennis C.

    2010-07-15

    There exists an increasing need to develop a reliable method to detect trace contaminants in fuel gas derived from coal gasification. While Hg is subject to current and future regulations, As, Se, and P emissions may eventually be regulated. Sorbents are the most promising technology for the removal of contaminants from coal-derived fuel gas, and it will be important to develop a rapid analytical detection method to ensure complete removal and determine the ideal time for sorbent replacement/regeneration in order to reduce costs. This technical note explores the use of a commercial gas chromatography/ion trap mass spectrometry system for the detection of four gaseous trace contaminants in a simulated fuel gas. Quantitative, repeatable detection with limits at ppbv to ppmv levels were obtained for arsine (AsH3), phosphine (PH3), and hydrogen selenide (H2Se), while qualitative detection was observed for mercury. Decreased accuracy and response caused by the primary components of fuel gas were observed.

  7. Subsurface detection of fossil fuel pollutants by photoionization and gas chromatography/mass spectrometry.

    PubMed

    Robbat, Albert; Considine, Thomas; Antle, Patrick M

    2010-09-01

    This paper describes analysis of environmental pollutants at depth without bringing sample to the surface. It is based on an improved 3-stage Peltier freeze trap, which efficiently pre-concentrates volatile coal tar and petroleum hydrocarbons, and an integrated system for detecting pollutants on-line, in real-time by photoionization detection and quantitation by gas chromatography/mass spectrometry (GC/MS) as the probe is advanced into the subsurface. Findings indicate measurement precision and accuracy for volatiles meet EPA criteria for hazardous waste site investigations. When a Teflon membrane inlet is used to detect contaminants in groundwater, its 140 degrees C temperature limit restricts analyte collection in soil to C(2)-phenanthrenes. Two case studies demonstrate the probe is well-suited to tracking petroleum and coal tar plumes from source to groundwater.

  8. Report: Suitability of Leak Detection Technology for Use In Ethanol-Blended Fuel Service

    EPA Science Inventory

    As the use of biofuels has increased in the last decade, there has been a level of concern over the effect that ethanol blends have on the material compatibility and operability of existing infrastructure. The focus of this research is to determine whether leak detection (LD) te...

  9. The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples.

    PubMed

    Coulson, S A; Morgan-Smith, R K; Noble, D

    2000-01-01

    In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene.

  10. Detecting Industrial Chemicals in Water With Microbial Fuel Cells and Artificial Neural Networks

    DTIC Science & Technology

    2014-03-27

    Peak Height ppb parts per billion ppm parts per million RO reverse osmosis SR Subsidence Rate 1 DETECTING INDUSTRIAL...solutions was purified through reverse osmosis (RO). 4.3 Enrichment All MFCs were inoculated with activated sludge as a source of bacteria. Previous...since reverse osmosis has the capability of filtering out many of the trace metals often needed by bacteria. 60 Figure 25. Operating History

  11. Field Method for Detection of Metal Deactivator Additive in Jet Fuel

    DTIC Science & Technology

    2009-04-01

    sulphonic acid on the silica support. The SCX stationary phase is a silica gel with propylbenzenesulfonyl groups bound to the silica, Figure 6. S O O O...They can be grouped into three main categories based on the property of the additive they are detecting. The categories are the; a. Dispersant...was less prominent when lower concentrations of MDA were used. The elution properties of the copper and nickel MDA complexes was examined in a range

  12. In Situ Search for Extraterrestrial Life: A Microbial Fuel Cell-Based Sensor for the Detection of Photosynthetic Metabolism.

    PubMed

    Figueredo, Federico; Cortón, Eduardo; Abrevaya, Ximena C

    2015-09-01

    Microbial fuel cells (MFCs) are bioelectrochemical systems (BES) capable of harvesting electrons from redox reactions involved in metabolism. In a previous work, we used chemoorganoheterotrophic microorganisms from the three domains of life-Bacteria, Archaea, and Eukarya-to demonstrate that these BES could be applied to the in situ detection of extraterrestrial life. Since metabolism can be considered a common signature of life "as we know it," we extended in this study the ability to use MFCs as sensors for photolithoautotrophic metabolisms. To achieve this goal, two different photosynthetic microorganisms were used: the microalgae Parachlorella kessleri and the cyanobacterium Nostoc sp. MFCs were loaded with nonsterilized samples, sterilized samples, or sterilized culture medium of both microorganisms. Electric potential measurements were recorded for each group in single experiments or in continuum during light-dark cycles, and power and current densities were calculated. Our results indicate that the highest power and current density values were achieved when metabolically active microorganisms were present in the anode of the MFC. Moreover, when continuous measurements were performed during light-dark cycles, it was possible to see a positive response to light. Therefore, these BES could be used not only to detect chemoorganoheterotrophic metabolisms but also photolithoautotrophic metabolisms, in particular those involving oxygenic photosynthesis. Additionally, the positive response to light when using these BES could be employed to distinguish photosynthetic from nonphotosynthetic microorganisms in a sample.

  13. Laser application in the fabrication of gas-tagged capsules. A leak detection system

    SciTech Connect

    McCord, R.B.; Lysher, W.M.

    1993-12-01

    Encapsulation of a unique isotopic blend of krypton and xenon gas employs a special application of laser technology. The encapsulated gas is then used as the primary medium for detection and identification of failed nuclear fuel rods. The use of gas tagging as a means of detecting and identifying failed nuclear fuel rods has been successfully demonstrated and used by the Argonne National Laboratory, Experimental Breeder Reactor (EBR-2) Project, and the Westinghouse Hanford Company (WHC), Fast Flux Test Facility (FFTF) Fast Breeder Reactor Program. The Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan has selected this leak detection system for use in their MONJU Prototype Reactor fuel assemblies. The MONJU reactor is almost identical in design to the highly successful FFTF reactor, which is currently in standby status.

  14. Failed State: A New (Old) Definition

    DTIC Science & Technology

    2010-04-21

    term failed state is very ambiguous. Noam Chomsky controversially defines failed state in such a manner that the United States is a failed state. His...28. 2 Noam Chomsky , Failed States: The Abuse of Power and the Assault on Democracy (New York: Metropolitan Books, 2006), 2. 4 state are...Center for Systemic Peace. “Polity IV Project.” http://www.systemicpeace.org/ polity/polity4.htm (accessed March 18, 2010). Chomsky , Noam

  15. Hidden disbond detection in spent nuclear fuel storage systems using air-coupled ultrasonics

    NASA Astrophysics Data System (ADS)

    Song, Homin; Popovics, John S.

    2016-04-01

    This paper studies an air-coupled ultrasonic scanning approach for damage assessment in steel-clad concrete structures. An air-coupled ultrasonic sender generates guided plate waves in the steel cladding and a small contact-type receiver measures the corresponding wave responses. A frequency-wavenumber (f-k) domain signal filtering technique is used to isolate the behavior of the fundamental symmetric (S0) mode of the guided plate waves. The behavior of the S0 mode is sensitive to interface bonding conditions. The proposed inspection approach is verified by a series of experiments performed on laboratory-scale specimens. The experimental results demonstrate that hidden disbond between steel cladding and underlying concrete substrate can be successfully detected with the ultrasonic test setup and the f-k domain signal filtering technique.

  16. Application of capillary electrophoresis with laser-induced fluorescence detection for the determination of trace neodymium in spent nuclear fuel using complexation with an emissive macrocyclic polyaminocarboxylate probe.

    PubMed

    Haraga, Tomoko; Saito, Shingo; Sato, Yoshiyuki; Asai, Shiho; Hanzawa, Yukiko; Hoshino, Hitoshi; Shibukawa, Masami; Ishimori, Ken-ichiro; Takahashi, Kuniaki

    2014-01-01

    A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by capillary electrophoresis with laser-induced fluorescence detection using a fluorescent probe having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 ± 3% recovery. This is due to high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role (log K(Ln-L-OH) = 3.9-5.3).

  17. Pathophysiology of the failing heart.

    PubMed

    McElroy, P A; Shroff, S G; Weber, K T

    1989-02-01

    Cardiac (or myocardial) failure of acute onset or of chronic duration is the result of a structural and/or biochemical remodeling of the myocardium. This, in turn, compromises the contractile performance of the myocardium. The hypertrophic growth of myocytes and the architectural transformation of ventricular chamber size and shape--while initially useful compensatory responses--do not prevent the inevitable appearance of pump failure where oxygen delivery to the metabolizing tissues becomes inadequate. Indeed, the severity of cardiac failure can be judged from the level of oxygen consumption that elicits this state of impaired oxygen supply and demand. A better understanding of the mechanical behavior of the ventricular chamber, including its elastic and resistive properties, together with recent advances in our ability to measure instantaneous ventricular pressure and volume, may prove useful in identifying pathologic features of hypertrophy and dilatation in individual patients. In grading the severity of failure and comparing groups of patients, a normalization of the mechanical parameters by differences in chamber size, shape, and mass is necessary. Symptomatic cardiac failure, based invariably on inadequate oxygen delivery and/or pulmonary congestion, is more commonly the result of ventricular systolic dysfunction. Abnormalities in diastolic function, including ventricular relaxation and filling, while less common and often associated with preserved systolic pump function, do occur. Finally, it must be recognized that the failing ventricle carries an additional hydraulic load that arises from the arterial circulation to which it is coupled.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Applying Infrared Thermography as a Quality-Control Tool for the Rapid Detection of Proton-Electrolyte-Membrane-Fuel-Cell Catalyst-Layer-Thickness Variations

    SciTech Connect

    Aieta, N. V.; Das, P. K.; Perdue, A.; Bender, G.; Herring, A. M.; Weber, A. Z.; Ulsh, M. J.

    2012-08-01

    As fuel cells become more prominent, new manufacturing and production methods are needed to enable increased volumes with high quality. One necessary component of this industrial growth will be the accurate measurement of the variability of a wide range of material properties during the manufacturing process. In this study, a method to detect defects in fuel cell catalyst layers is investigated through experiment and mathematical simulation. The method uses infrared thermography and direct-current electronic-excitation methods to detect variations in platinum-containing catalyst-layer thickness with high spatial and temporal resolution. Data analysis, operating-condition impacts, and detection limits are explored, showing the measurement of defects on the millimeter length scale. Overall, the experimental and modeling results demonstrate great potential of this technique as a nondestructive method to measure defects that is amenable to use on roll-to-roll manufacturing lines.

  19. System for detecting leaks in underground fuel tanks and the like

    SciTech Connect

    Horner, J.A.

    1989-12-12

    This patent describes a system for detecting leaks in incompletely filled liquid storage tanks, incorporating projecting fill and vent pipes, which systems are connected with a liquid withdrawal system normally isolated from the atmosphere. It comprises: means for filling the tank space above the surface of the liquid therein with a gas under a pressure greater than atmospheric pressure and maintaining a gaseous pressure on the the liquid surface; a fluid containing receptacle disposed in the tank space above the surface of the liquid; means including a pair of tubular parts, one extending to a predetermined depth of submersion in the liquid in the tank and the other extending to a predetermined depth of submersion in the fluid in the receptacle for forcing a continuous stream of bubbles of gas into the the liquid and into the the fluid whereby the resistance to gas introduction is influenced in each by the composite effect of the pressure of the gas on the surface of the liquid and the head at which the bubbles are introduced; and means for balancing the pressure required to flow the continuous stream of bubbles into the liquid against the pressure required to flow the continuous stream of bubbles into the fluid and indicating any differential pressure variation over a time period.

  20. Millimeter Wave Detection of Localized Anomalies in the Space Shuttle External Fuel Tank Insulating Foam and Acreage Heat Tiles

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Case, J. T.; Zoughi, R.; Hepburn, F.

    2005-01-01

    The Space Shuttle Columbia's catastrophic accident emphasizes the growing need for developing and applying effective, robust and life-cycle oriented nondestructive testing (NDT) methods for inspecting the shuttle external fuel tank spray on foam insulation (SOFI) and its protective acreage heat tiles. Millimeter wave NDT techniques were one of the methods chosen for evaluating their potential for inspecting these structures. Several panels with embedded anomalies (mainly voids) were produced and tested for this purpose. Near-field and far-field millimeter wave NDT methods were used for producing millimeter wave images of the anomalies in SOFI panel and heat tiles. This paper presents the results of an investigation for the purpose of detecting localized anomalies in two SOFI panels and a set of heat tiles. To this end, reflectometers at a relatively wide range of frequencies (Ka-band (26.5 - 40 GHz) to W-band (75 - 110 GHz)) and utilizing different types of radiators were employed. The results clearly illustrate the utility of these methods for this purpose.

  1. Determination of aflatoxins in air samples of refuse-derived fuel by thin-layer chromatography with laser-induced fluorescence spectrometric detection

    SciTech Connect

    Bicking, M.K.L.; Kniseley, R.N.; Svec, H.J.

    1983-02-01

    An analytical method is described which allows determination of aflatoxins in a complex matrix. An apparatus has been developed that quantitates fluorescent compounds on thin-layer chromatography plates. A nitrogen laser excitation source produces a detection limit of 10 pg for four aflatoxins. Aflatoxin B1 has been found at levels up to 17 ppb in solid samples collected from the air at a plant which produces refuse-derived fuel. 7 figures, 1 table.

  2. Analytical applications of microbial fuel cells. Part II: Toxicity, microbial activity and quantification, single analyte detection and other uses.

    PubMed

    Abrevaya, Ximena C; Sacco, Natalia J; Bonetto, Maria C; Hilding-Ohlsson, Astrid; Cortón, Eduardo

    2015-01-15

    Microbial fuel cells were rediscovered twenty years ago and now are a very active research area. The reasons behind this new activity are the relatively recent discovery of electrogenic or electroactive bacteria and the vision of two important practical applications, as wastewater treatment coupled with clean energy production and power supply systems for isolated low-power sensor devices. Although some analytical applications of MFCs were proposed earlier (as biochemical oxygen demand sensing) only lately a myriad of new uses of this technology are being presented by research groups around the world, which combine both biological-microbiological and electroanalytical expertises. This is the second part of a review of MFC applications in the area of analytical sciences. In Part I a general introduction to biological-based analytical methods including bioassays, biosensors, MFCs design, operating principles, as well as, perhaps the main and earlier presented application, the use as a BOD sensor was reviewed. In Part II, other proposed uses are presented and discussed. As other microbially based analytical systems, MFCs are satisfactory systems to measure and integrate complex parameters that are difficult or impossible to measure otherwise, such as water toxicity (where the toxic effect to aquatic organisms needed to be integrated). We explore here the methods proposed to measure toxicity, microbial metabolism, and, being of special interest to space exploration, life sensors. Also, some methods with higher specificity, proposed to detect a single analyte, are presented. Different possibilities to increase selectivity and sensitivity, by using molecular biology or other modern techniques are also discussed here.

  3. Evaluation of immunoassay-based field test kits for the detection of petroleum fuel hydrocarbons in soil

    SciTech Connect

    Waters, L.C.; Palausky, M.A.; Counts, R.W.; Jenkins, R.A.

    1995-04-01

    The objectives of this project are to identify, experimentally evaluate and implement the use of alternative field screening methods that are specific for environmental contaminants of interest and concern to the Department of Energy. Immunochemical techniques are rapidly becoming a significant component in the arsenal of field screening methods. Analytical results obtained by immunoassay have been shown to correlate well with those obtained by traditional laboratory methods. Also, the use of immunoassay-based field screening methods can significantly reduce the cost and time required for environmental assessment. The authors are currently evaluating the effectiveness of several immunoassay-based test kits for detecting petroleum fuel hydrocarbons in soil. Evaluations of two kits, one a semiquantitative assay and the other a quantitative assay, have been completed. The samples analyzed were either solvent or soil spiked with either a mixture of benzene, toluene, ethylbenzene and the three isomers of xylene (BTEX), or gasoline. The kits performed well and according to the manufacturers` claims. Of the 50 assays made with the semiquantitative test, the concentrations of 44 samples were correctly determined. The other six samples were determined to be false positives. A soil matrix effect was observed that could account for some of the false positive results. Experimental results using the quantitative test with BTEX (68 assays) correlated well with those expected; R{sup 2} of 0.976 to 0.983 with slopes of 0.94 to 0.97. With gasoline (38 assays) R{sup 2} values of 0.957 to 0.987 and slopes of 0.76 to 0.78 were obtained. The lower slopes with gasoline are indicative of the lower immunoreactivity of that particular sample of gasoline relative to BTEX.

  4. Fuel injection system

    SciTech Connect

    Miyaki, M.; Iwanaga, T.; Fujisawa, H.

    1988-10-18

    This patent describes a fuel injection system for a diesel engine comprising: condition detection means for detecting operating conditions of the diesel engine including a rotational position thereof; low pressure fuel supply means for supplying fuel at a low pressure at an output port thereof; high pressure fuel pump means, having a pump chamber communicating with the output port of the low pressure fuel supply means, and plunger means reciprocable within the pump chamber for introducing fuel from the output port of the low pressure fuel supply means into the pump chamber during a movement in a predetermined direction of the plunger means and for pressurizing the introduced fuel during a movement of the plunger means in the opposite direction so that pressurized fuel is delivered from the high pressure fuel pump means at an output port thereof; common rail fuel storage means, connected to the output port of the high pressure fuel pump means, for storing pressurized fuel delivered from the high pressure pump therein at a substantially continuous pressure.

  5. Why Waveform Correlation Sometimes Fails

    NASA Astrophysics Data System (ADS)

    Carmichael, J.

    2015-12-01

    Waveform correlation detectors used in explosion monitoring scan noisy geophysical data to test two competing hypotheses: either (1) an amplitude-scaled version of a template waveform is present, or, (2) no signal is present at all. In reality, geophysical wavefields that are monitored for explosion signatures include waveforms produced by non-target sources that are partially correlated with the waveform template. Such signals can falsely trigger correlation detectors, particularly at low thresholds required to monitor for smaller target explosions. This challenge is particularly formidable when monitoring known test sites for seismic disturbances, since uncatalogued natural seismicity is (generally) more prevalent at lower magnitudes, and could be mistaken for small explosions. To address these challenges, we identify real examples in which correlation detectors targeting explosions falsely trigger on both site-proximal earthquakes (Figure 1, below) and microseismic "noise". Motivated by these examples, we quantify performance loss when applying these detectors, and re-evaluate the correlation-detector's hypothesis test. We thereby derive new detectors from more general hypotheses that admit unknown background seismicity, and apply these to real data. From our treatment, we derive "rules of thumb'' for proper template and threshold selection in heavily cluttered signal environments. Last, we answer the question "what is the probability of falsely detecting an earthquake collocated at a test site?", using correlation detectors that include explosion-triggered templates. Figure Top: An eight-channel data stream (black) recorded from an earthquake near a mine. Red markers indicate a detection. Middle: The correlation statistic computed by scanning the template against the data stream at top. The red line indicates the threshold for event declaration, determined by a false-alarm on noise probability constraint, as computed from the signal-absent distribution using

  6. Failed supernovae explain the compact remnant mass function

    SciTech Connect

    Kochanek, C. S.

    2014-04-10

    One explanation for the absence of higher mass red supergiants (16.5 M {sub ☉} ≲ M ≲ 25 M {sub ☉}) as the progenitors of Type IIP supernovae (SNe) is that they die in failed SNe creating black holes. Simulations show that such failed SNe still eject their hydrogen envelopes in a weak transient, leaving a black hole with the mass of the star's helium core (5-8 M {sub ☉}). Here we show that this naturally explains the typical masses of observed black holes and the gap between neutron star and black hole masses without any fine-tuning of stellar mass loss, binary mass transfer, or the SN mechanism, beyond having it fail in a mass range where many progenitor models have density structures that make the explosions more likely to fail. There is no difficulty including this ∼20% population of failed SNe in any accounting of SN types over the progenitor mass function. And, other than patience, there is no observational barrier to either detecting these black hole formation events or limiting their rates to be well below this prediction.

  7. Presence of estrogenic activity from emission of fossil fuel combustion as detected by a recombinant yeast bioassay

    NASA Astrophysics Data System (ADS)

    Wang, Jingxian; Wu, Wenzhong; Henkelmann, Bernhard; You, Li; Kettrup, Antonius; Schramm, Karl-Werner

    Estrogenic activities of emission samples generated by fossil fuel combustion were investigated with human estrogen receptor (ER) recombinant yeast bioassay. The results showed that there were weak but clear estrogenic activities in combustion emissions of fossil fuels including coal, petroleum, and diesel. The estrogenic relative potency (RP) of fossil fuel combustion was the highest in petroleum-fired car, followed by coal-fired stove, diesel-fired agrimotor, coal-fired electric power station. On the other hand, the estrogenic relative inductive efficiency (RIE) was the highest in coal-fired stove and coal-fired electric power station, followed by petroleum-fired car and diesel-fired agrimotor. The estrogenic activities in the sub-fractions from chromatographic separation of emitted materials were also determined. The results indicated that different chemical fractions in these complex systems have different estrogenic potencies. The GC/MS analysis of the emission showed that there were many aromatic carbonyls, big molecular alcohol, PAHs and derivatives, and substituted phenolic compounds and derivatives which have been reported as environmental estrogens. The existence of estrogenic substances in fossil fuel combustion demands further investigation of their potential adverse effects on human and on the ecosystem. The magnitude of pollution due to global usage of fossil fuels makes it imperative to understand the issue of fossil fuel-derived endocrine activities and the associated health risks, particularly the aggregated risks stemmed from exposure to toxicants of multiple sources.

  8. DIESEL FUEL LUBRICATION

    SciTech Connect

    Qu, Jun

    2012-01-01

    The diesel fuel injector and pump systems contain many sliding interfaces that rely for lubrication upon the fuels. The combination of the poor fuel lubricity and extremely tight geometric clearance between the plunger and bore makes the diesel fuel injector vulnerable to scuffing damage that severely limits the engine life. In order to meet the upcoming stricter diesel emission regulations and higher engine efficiency requirements, further fuel refinements that will result in even lower fuel lubricity due to the removal of essential lubricating compounds, more stringent operation conditions, and tighter geometric clearances are needed. These are expected to increase the scuffing and wear vulnerability of the diesel fuel injection and pump systems. In this chapter, two approaches are discussed to address this issue: (1) increasing fuel lubricity by introducing effective lubricity additives or alternative fuels, such as biodiesel, and (2) improving the fuel injector scuffing-resistance by using advanced materials and/or surface engineering processes. The developing status of the fuel modification approach is reviewed to cover topics including fuel lubricity origins, lubricity improvers, alternative fuels, and standard fuel lubricity tests. The discussion of the materials approach is focused on the methodology development for detection of the onset of scuffing and evaluation of the material scuffing characteristics.

  9. Is journalism failing on climate?

    NASA Astrophysics Data System (ADS)

    Rahmstorf, Stefan

    2012-12-01

    How can we build a reliable and affordable energy supply based on renewables? How rapidly do we need to cut greenhouse gas emissions to keep climate change within manageable bounds? What does it take to maintain a stable common currency of different nations? These are just a few examples of questions that are critical for our future and that require an understanding of complex systems—the energy system, the climate system, the financial system. Finding sound answers to these questions requires sophisticated scientific analysis and expert knowledge; a lay person's intuition will clearly not suffice. Yet, decisions in a democracy are (and should be!) taken by politicians and the voting public who are not usually scientific experts. Hence the well-being of our societies—and even more so the living conditions of future generations, which are defined by the decisions we take today—depends on the wider public being well informed about the state of scientific knowledge and discourse. The media are the most important means by which lay people obtain their information about science. Good science journalism is therefore a decisive factor for the long-term success of modern society. Good science journalism clearly must be critical journalism, and it requires journalists who know what is what, who can put things into a perspective, and who are able to make well-informed judgements. After all, the role of science journalism is not simply to act as a 'translator' who conveys the findings of scientists in a language understandable to lay people. Rather, good science journalism will provide the public with a realistic impression of what is well established in science and what are current 'hot topics', uncertainties and controversies. It will also discuss the methods and social context of the scientific endeavour. There is ample evidence that in the area of climate science, journalism too often is failing to deliver this realistic picture to its audience, despite many good

  10. Highly sensitive detection of neodymium ion in small amount of spent nuclear fuel samples using novel fluorescent macrocyclic hexadentate polyaminocarboxylate probe in capillary electrophoresis-laser-induced fluorescence detection.

    PubMed

    Saito, Shingo; Sato, Yoshiyuki; Haraga, Tomoko; Nakano, Yuta; Asai, Shiho; Kameo, Yutaka; Takahashi, Kuniaki; Shibukawa, Masami

    2012-04-06

    A rapid and high-sensitive detection method for the total concentration of Nd ion (total Nd) in a small amount of a spent nuclear fuel sample is urgently required since the precise quantification of total Nd ion makes it possible for burnup (degree of fuel consumption) to be determined. In this work, a capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) is proposed for the analysis of total Nd in a spent fuel sample solution, with the use of a newly synthesized metal fluorescent probe which has a fluorescein and a macrocylic hexadentate chelating group, FTC-ABNOTA, for lanthanide (Ln) ions. Ln ions were derivatized to form a strongly fluorescent complex with the probe to suppress the quenching of the ligand-centered emission. The detection of Ln complexes in the CE-LIF indicated that the interaction between Ln ions and the FTC-ABNOTA was strong enough not to dissociate during migration. The mutual separation among the Ln-FTC-ABNOTA complexes in CE-LIF was achieved by pH control providing a dynamic ternary complexation (DTC) with hydroxide ions. Using the DTC separation mode, a high resolution of Nd from other Ln ions with high resolution of 1.3-1.9 and a theoretical plate number of 68,000, and a very low detection limit of 22 pM (3.2 ppt, 0.11 attomole amount basis) were successfully obtained. A simulated spent fuel sample containing various metal ions was examined in this method with a good quantification result of 102.1% recovery obtained even with a large excess of U.

  11. Fossil fuels -- future fuels

    SciTech Connect

    1998-03-01

    Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

  12. In situ measurement technique for simultaneous detection of K, KCl, and KOH vapors released during combustion of solid biomass fuel in a single particle reactor.

    PubMed

    Sorvajärvi, Tapio; DeMartini, Nikolai; Rossi, Jussi; Toivonen, Juha

    2014-01-01

    A quantitative and simultaneous measurement of K, KCl, and KOH vapors from a burning fuel sample combusted in a single particle reactor was performed using collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) with a time resolution of 0.2 s. The previously presented CPFAAS technique was extended in this work to cover two consecutive fragmentation pulses for the photofragmentation of KCl and KOH. The spectral overlapping of the fragmentation spectra of KCl and KOH is discussed, and a linear equation system for the correction of the spectral interference is introduced. The detection limits for KCl, KOH, and K with the presented measurement arrangement and with 1 cm sample length were 0.5, 0.1, and 0.001 parts per million, respectively. The experimental setup was applied to analyze K, KCl, and KOH release from 10 mg spruce bark samples combusted at the temperatures of 850, 950, and 1050 °C with 10% of O2. The combustion experiments provided data on the form of K vapors and their release during different combustion phases and at different temperatures. The measured release histories agreed with earlier studies of K release. The simultaneous direct measurement of atomic K, KCl, and KOH will help in the impact of both the form of K in the biomass and fuel variables, such as particle size, on the release of K from biomass fuels.

  13. A serach for 'failed clusters' of galaxies

    NASA Technical Reports Server (NTRS)

    Tucker, W. H.; Tananbaum, H.; Remillard, R. A.

    1995-01-01

    We describe a search for a new type of object - large clouds of hot gas with no visible galaxies - which we call failed clusters of galaxies. We calculate the expected X-ray luminosity, temperature, and angular diameter of such objects as a function of total cloud mass and convert the results to expected X-ray fluxes from failed clusters at different redshifts. Using the Einstein Imaging Proportional Counter (IPC) database, we establish a strategy to search for candidate failed clusters. From this initial screening of 1435 IPC fields, 17 candidates are selected for more detailed analysis, which indicates that 10 of these are very probably extended X-ray sources. Optical follow-up on the 10 prime candidates finds eight clusters of galaxies (including six reproted for the first time in this paper), one stellar identification, and one without an obvious optical counterpart (the candidate with the weakest evidence for X-ray extent). Investigation of several candidates with less evidence for X-ray extent yields two additional new clusters of galaxies. A conservative comparison of our results with the Einstein Extended Medium Sensitivity Survey demonstrates that failed clusters are a relatively unimportant contributor to the mass density of the universe. Our inability to find failed clusters is consistent with the hierarchical clustering scenario for the formation of galaxies and clusters.

  14. Forest fuel treatment detection using multi-temporal airborne Lidar data and high resolution aerial imagery ---- A case study at Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Su, Y.; Guo, Q.; Collins, B.; Fry, D.; Kelly, M.

    2014-12-01

    Forest fuel treatments (FFT) are often employed in Sierra Nevada forest (located in California, US) to enhance forest health, regulate stand density, and reduce wildfire risk. However, there have been concerns that FFTs may have negative impacts on certain protected wildlife species. Due to the constraints and protection of resources (e.g., perennial streams, cultural resources, wildlife habitat, etc.), the actual FFT extents are usually different from planned extents. Identifying the actual extent of treated areas is of primary importance to understand the environmental influence of FFTs. Light detection and ranging (Lidar) is a powerful remote sensing technique that can provide accurate forest structure measurements, which provides great potential to monitor forest changes. This study used canopy height model (CHM) and canopy cover (CC) products derived from multi-temporal airborne Lidar data to detect FFTs by an approach combining a pixel-wise thresholding method and a object-of-interest segmentation method. We also investigated forest change following the implementation of landscape-scale FFT projects through the use of normalized difference vegetation index (NDVI) and standardized principle component analysis (PCA) from multi-temporal high resolution aerial imagery. The same FFT detection routine was applied on the Lidar data and aerial imagery for the purpose of comparing the capability of Lidar data and aerial imagery on FFT detection. Our results demonstrated that the FFT detection using Lidar derived CC products produced both the highest total accuracy and kappa coefficient, and was more robust at identifying areas with light FFTs. The accuracy using Lidar derived CHM products was significantly lower than that of the result using Lidar derived CC, but was still slightly higher than using aerial imagery. FFT detection results using NDVI and standardized PCA using multi-temporal aerial imagery produced almost identical total accuracy and kappa coefficient

  15. Fail-safe bidirectional valve driver

    NASA Technical Reports Server (NTRS)

    Fujimoto, H.

    1974-01-01

    Cross-coupled diodes are added to commonly used bidirectional valve driver circuit to protect circuit and power supply. Circuit may be used in systems requiring fail-safe bidirectional valve operation, particularly in chemical- and petroleum-processing control systems and computer-controlled hydraulic or pneumatic systems.

  16. The Art of Saving a Failing School

    ERIC Educational Resources Information Center

    Stein, Les

    2012-01-01

    While the debate continues over whether to close failing schools or attempt fixing them, the author asserts that the solution most often lies in assigning strong leaders to them who will take definite and immediate action. Reviewing his own success turning around schools, he says creating a sense of urgency, unloading poor performing staff, and…

  17. Examination of a Failed Professional Learning Community

    ERIC Educational Resources Information Center

    Sims, Rachel L.; Penny, G. Richard

    2015-01-01

    Schools are using various forms of professional learning communities (PLCs) in order to increase student achievement and improve educational practices through enhanced communication and collaboration among teachers. This study examined a PLC that had too narrow a focus and failed therefore to affect student achievement. A critical shortcoming of…

  18. H2O2 detection analysis of oxygen reduction reaction on cathode and anode catalysts for polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Kishi, Akira; Shironita, Sayoko; Umeda, Minoru

    2012-01-01

    The generation percentage of H2O2 during oxygen reduction reaction (ORR) at practical powder electrocatalysts was evaluated using a scanning electrochemical microscope (SECM). We employed a porous microelectrode that contains electrocatalysts, namely, Pt/C, Pt-Co/C, and Pt-Ru/C as the oxygen reduction electrode of the SECM, and the Pt microelectrode was used as the H2O2 detector. First, the H2O2 generation amount at Pt/Cs was measured by changing the Pt loading amount. A Pt/C with a higher Pt loading has a higher ORR activity and generates a larger amount of H2O2. However, the percentage of H2O2 generated with respect to the ORR is the same regardless of the Pt loading amount. Next, H2O2 generation is markedly suppressed at the Pt-Co/C and Pt-Ru/C in the potential ranges of practical fuel cell cathode and anode, respectively. This explains that the Pt-Co/C is effective when used as a cathode, and the anode Pt-Ru/C enables the reduction of the H2O2 generation even if O2 crossleak occurs in the practical polymer electrolyte fuel cell.

  19. DNA-fueled molecular machine enables enzyme-free target recycling amplification for electronic detection of microRNA from cancer cells with highly minimized background noise.

    PubMed

    Shi, Kai; Dou, Baoting; Yang, Cuiyun; Chai, Yaqin; Yuan, Ruo; Xiang, Yun

    2015-08-18

    The variations in microRNA (miRNA) expression levels can be useful biomarkers for the diagnosis of different cancers. In this work, on the basis of a new miRNA-triggered molecular machine for enzyme-free target recycling signal amplification, the development of a simple electronic sensor for highly sensitive detection of miRNA-21 from human breast cancer cells is described. The three-stand DNA duplex probes are self-assembled on the gold electrode surface to fabricate the sensor. The miRNA-21 target binds to the terminal toehold region of the probes, displaces one of the short strands through toehold-mediated strand displacement reactions, and exposes the secondary toehold region for subsequent hybridization with the methylene blue (MB)-modified DNA fuel strand, which further displaces both the miRNA-21 target and the other short strand to activate the operation of the molecular machine. As a result, the miRNA-21 target is cyclically reused, and many MB-DNA fuel strands are attached to the sensor surface, leading to a significantly amplified current response for sensitive detection of miRNA-21 down to 1.4 fM. The developed sensor also shows high sequence discrimination capability and can be used to monitor miRNA-21 expression levels in cancer cells. Moreover, this sensor avoids the involvement of any enzymes for target recycling amplification and features with highly minimized background noise for miRNA detection, which makes this method hold great potential for convenient monitoring of different miRNA biomarkers for early diagnosis of various cancers.

  20. Alternative Fuels

    EPA Pesticide Factsheets

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  1. Fuel pin

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Leggett, Robert D.; Baker, Ronald B.

    1989-01-01

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  2. Fuel pin

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Leggett, R.D.; Baker, R.B.

    1987-11-24

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  3. Fuel pin

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Leggett, Robert D.; Baker, Ronald B.

    1989-10-03

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  4. Development of a Raman spectroscopy technique to detect alternate transportation fuel hydrocarbon intermediates in complex combustion environments.

    SciTech Connect

    Ekoto, Isaac W.; Barlow, Robert S.

    2012-12-01

    Spontaneous Raman spectra for important hydrocarbon fuels and combustion intermediates were recorded over a range of low-to-moderate flame temperatures using the multiscalar measurement facility located at Sandia/CA. Recorded spectra were extrapolated to higher flame temperatures and then converted into empirical spectral libraries that can readily be incorporated into existing post-processing analysis models that account for crosstalk from overlapping hydrocarbon channel signal. Performance testing of the developed libraries and reduction methods was conducted through an examination of results from well-characterized laminar reference flames, and was found to provide good agreement. The diagnostic development allows for temporally and spatially resolved flame measurements of speciated hydrocarbon concentrations whose parent is more chemically complex than methane. Such data are needed to validate increasingly complex flame simulations.

  5. Excitation/Detection Strategies for OH Planar Laser-Induced Fluorescence Measurements in the Presence of Interfering Fuel Signal and Absorption Effects

    NASA Technical Reports Server (NTRS)

    Heath, Christopher M.; Anderson, Robert C.; Hicks, Yolanda R.

    2011-01-01

    Planar laser-induced fluorescence (PLIF) excitation/detection methods have been applied to obtain spatial distributions of the hydroxyl [OH] reacting intermediary and hydrocarbon [HC] primary species in laminar and turbulent combustion reactions. In this report, broadband and narrowband excitation/filtering techniques are explored to identify an optimal experimental configuration yielding significant fluorescent signal with low absorption losses. The combustion environments analyzed include 1) a laminar non-premixed methane/air flame and 2) a turbulent, non-premixed Jet-A/air fueled flame within a lean flame tube combustor. Hydrocarbon-based fuel and OH were excited via the R1 (1), R1(10) and R2(7) transitions of the A(sup 2)Epsilon(+) X(sup 2)pi(1,0) band using a broadband Nd:YAG pumped optical parametric oscillator (OPO) and narrowband Nd:YAG/dye laser with ultraviolet frequency extension (UVX) package. Variables tested for influence on fluorescent signal and absorption characteristics were excitation line, laser energy, exciting linewidth, combustion reactants, and test flow conditions. Results are intended to guide the transition from a dye/UVX laser to an OPO system for performing advanced diagnostics of low-emission combustion concepts.

  6. Checklist for transition to new highway fuel(s).

    SciTech Connect

    Risch, C.; Santini, D.J.

    2011-12-15

    Transportation is vital to the U.S. economy and society. As such, U.S. Presidents have repeatedly stated that the nation needs to reduce dependence on petroleum, especially for the highway transportation sector. Throughout history, highway transportation fuel transitions have been completed successfully both in United States and abroad. Other attempts have failed, as described in Appendix A: Historical Highway Fuel Transitions. Planning for a transition is critical because the changes can affect our nation's ability to compete in the world market. A transition will take many years to complete. While it is tempting to make quick decisions about the new fuel(s) of choice, it is preferable and necessary to analyze all the pertinent criteria to ensure that correct decisions are made. Doing so will reduce the number of changes in highway fuel(s). Obviously, changes may become necessary because of occurrences such as significant technology breakthroughs or major world events. With any and all of the possible transitions to new fuel(s), the total replacement of gasoline and diesel fuels is not expected. These conventional fuels are envisioned to coexist with the new fuel(s) for decades, while the revised fuel and vehicle infrastructures are implemented. The transition process must analyze the needs of the primary 'players,' which consist of the customers, the government, the fuel industry, and the automotive industry. To maximize the probability of future successes, the prime considerations of these groups must be addressed. Section 2 presents a succinct outline of the Checklist. Section 3 provides a brief discussion about the groupings on the Checklist.

  7. Analysis of failed nuclear plant components

    SciTech Connect

    Diercks, D.R.

    1992-07-01

    Argonne National Laboratory has conducted analyses of failed components from nuclear power generating stations since 1974. The considerations involved in working with and analyzing radioactive components are reviewed here, and the decontamination of these components is discussed. Analyses of four failed components from nuclear plants are then described to illustrate the kinds of failures seen in service. The failures discussed are (a) intergranular stress corrosion cracking of core spray injection piping in a boiling water reactor, (b) failure of canopy seal welds in adapter tube assemblies in the control rod drive head of a pressure water reactor, (c) thermal fatigue of a recirculation pump shaft in a boiling water reactor, and (d) failure of pump seal wear rings by nickel leaching in a boiling water reactor.

  8. Failed back surgery syndrome: current perspectives

    PubMed Central

    Baber, Zafeer; Erdek, Michael A

    2016-01-01

    The treatment of failed back surgery syndrome (FBSS) can be equally challenging to surgeons, pain specialists, and primary care providers alike. The onset of FBSS occurs when surgery fails to treat the patient’s lumbar spinal pain. Minimizing the likelihood of FBSS is dependent on determining a clear etiology of the patient’s pain, recognizing those who are at high risk, and exhausting conservative measures before deciding to go into a revision surgery. The workup of FBSS includes a thorough history and physical examination, diagnostic imaging, and procedures. After determining the cause of FBSS, a multidisciplinary approach is preferred. This includes pharmacologic management of pain, physical therapy, and behavioral modification and may include therapeutic procedures such as injections, radiofrequency ablation, lysis of adhesions, spinal cord stimulation, and even reoperations. PMID:27853391

  9. Laboratory and Field Testing of Commercially Available Detectors for the Identification of Chemicals of Interest in the Nuclear Fuel Cycle for the Detection of Undeclared Activities

    SciTech Connect

    Carla Miller; Mary Adamic; Stacey Barker; Barry Siskind; Joe Brady; Warren Stern; Heidi Smartt; Mike McDaniel; Mike Stern; Rollin Lakis

    2014-07-01

    Traditionally, IAEA inspectors have focused on the detection of nuclear indicators as part of infield inspection activities. The ability to rapidly detect and identify chemical as well as nuclear signatures can increase the ability of IAEA inspectors to detect undeclared activities at a site. Identification of chemical indicators have been limited to use in the analysis of environmental samples. Although IAEA analytical laboratories are highly effective, environmental sample processing does not allow for immediate or real-time results to an IAEA inspector at a facility. During a complementary access inspection, under the Additional Protocol, the use of fieldable technologies that can quickly provide accurate information on chemicals that may be indicative of undeclared activities can increase the ability of IAEA to effectively and efficiently complete their mission. The Complementary Access Working Group (CAWG) is a multi-laboratory team with members from Brookhaven National Laboratory, Idaho National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratory. The team identified chemicals at each stage of the nuclear fuel cycle that may provide IAEA inspectors with indications that proliferation activities may be occurring. The group eliminated all indicators related to equipment, technology and training, developing a list of by-products/effluents, non-nuclear materials, nuclear materials, and other observables. These proliferation indicators were prioritized based on detectability from a conduct of operations (CONOPS) perspective of a CA inspection (for example, whether an inspector actually can access the S&O or whether it is in process with no physical access), and the IAEA’s interest in the detection technology in conjunction with radiation detectors. The list was consolidated to general categories (nuclear materials from a chemical detection technique, inorganic chemicals, organic chemicals, halogens, and miscellaneous materials). The team

  10. Neurolysis for failed tarsal tunnel surgery.

    PubMed

    Yalcinkaya, Merter; Ozer, Utku Erdem; Yalcin, M Burak; Bagatur, A Erdem

    2014-01-01

    The purpose of the present study was to investigate the causes of failure after tarsal tunnel release and the operative findings in the secondary interventions and the outcomes. The data from 8 patients who had undergone revision surgery for failed tarsal tunnel release at least 12 months earlier were evaluated retrospectively. Only the patients with idiopathic tarsal tunnel syndrome were included, and all had unilateral symptoms. Neurophysiologic tests confirmed the clinical diagnosis of failed tarsal tunnel release in all patients. Magnetic resonance imaging revealed varicose veins within the tarsal tunnel in 1 patient (12.5%) and tenosynovitis in another (12.5%). Open tarsal tunnel release was performed in all patients, and the tibialis posterior nerve, medial and lateral plantar nerves (including the first branch of the lateral plantar nerve), and medial calcaneal nerve were released in their respective tunnels, and the septum between the tunnels was resected. The outcomes were assessed according to subjective patient satisfaction as excellent, good, fair, or poor. During revision surgery, insufficient release of the tarsal tunnel, especially distally, was observed in all the patients, and fibrosis of the tibialis posterior nerve was present in 1 (12.5%). The outcomes according to subjective patient satisfaction were excellent in 5 (62.5%), good in 2 (25%), and fair in 1 (12.5%). The fair outcome was obtained in the patient with fibrosis of the nerve. Insufficient release of the tarsal tunnel was the main cause of failed tarsal tunnel release. Releasing the 4 distinct tunnels and permitting immediate mobilization provided satisfactory results in patients with failed tarsal tunnel release.

  11. Pass-Fail: How Is It Working?

    ERIC Educational Resources Information Center

    Chase, Clinton I.; And Others

    This study investigates the pass/fail (P/F) grading system. A sample of 154 Indiana University students was interviewed. Half of the group, 77 students, had not taken any P/F courses. Of the remaining 77 students, 42% had taken only one P/F course and most of the rest from two to five courses. Results of the student interview questionnaire…

  12. Fuel pump

    SciTech Connect

    Bellis, P.D.; Nesselrode, F.

    1991-04-16

    This patent describes a fuel pump. It includes: a fuel reservoir member, the fuel reservoir member being formed with fuel chambers, the chambers comprising an inlet chamber and an outlet chamber, means to supply fuel to the inlet chamber, means to deliver fuel from the outlet chamber to a point of use, the fuel reservoir member chambers also including a bypass chamber, means interconnecting the bypass chamber with the outlet chamber; the fuel pump also comprising pump means interconnecting the inlet chamber and the outlet chamber and adapted to suck fuel from the fuel supply means into the inlet chamber, through the pump means, out the outlet chamber, and to the fuel delivery means; the bypass chamber and the pump means providing two substantially separate paths of fuel flow in the fuel reservoir member, bypass plunger means normally closing off the flow of fuel through the bypass chamber one of the substantially separate paths including the fuel supply means and the fuel delivery means when the bypass plunger means is closed, the second of the substantially separate paths including the bypass chamber when the bypass plunger means is open, and all of the chambers and the interconnecting means therebetween being configured so as to create turbulence in the flow of any fuel supplied to the outlet chamber by the pump means and bypassed through the bypass chamber and the interconnecting means.

  13. Irradiation of three T-111 clad uranium nitride fuel pins for 8070 hours at 990 C (1815 F)

    NASA Technical Reports Server (NTRS)

    Slaby, J. G.; Siegel, B. L.; Gedeon, L.; Galbo, R. J.

    1973-01-01

    The design and successful operation of three tantalum alloy (Ta-8W-2Hf) clad uranium mononitride (UN) fuel pins irradiated for 8070 hr at 990 C (1815 F) is described. Two pin diameters having measured burnups of 0.47 and 0.90 uranium atom percent were tested. No clad failures or swelling was detected; however, postirradiation clad samples tested failed with 1 percent strain. The fuel density decrease was 2 percent, and the fission gas release was less than 0.05 percent. Isotropic fuel swelling, which averaged about 0.5 percent, was less than fuel pin assembly clearances. Thus the clad was not strained. Thermocouples with a modified hot zone operated at average temperatures to 1100 C (2012 F) without failure. Factors that influence the ability to maintain uniform clad temperature as well as the results of the heat transfer calculations are discussed.

  14. Nuclear fuel pin scanner

    DOEpatents

    Bramblett, Richard L.; Preskitt, Charles A.

    1987-03-03

    Systems and methods for inspection of nuclear fuel pins to determine fiss loading and uniformity. The system includes infeed mechanisms which stockpile, identify and install nuclear fuel pins into an irradiator. The irradiator provides extended activation times using an approximately cylindrical arrangement of numerous fuel pins. The fuel pins can be arranged in a magazine which is rotated about a longitudinal axis of rotation. A source of activating radiation is positioned equidistant from the fuel pins along the longitudinal axis of rotation. The source of activating radiation is preferably oscillated along the axis to uniformly activate the fuel pins. A detector is provided downstream of the irradiator. The detector uses a plurality of detector elements arranged in an axial array. Each detector element inspects a segment of the fuel pin. The activated fuel pin being inspected in the detector is oscillated repeatedly over a distance equal to the spacing between adjacent detector elements, thereby multiplying the effective time available for detecting radiation emissions from the activated fuel pin.

  15. New results from the NSRR experiments with high burnup fuel

    SciTech Connect

    Fuketa, Toyoshi; Ishijima, Kiyomi; Mori, Yukihide

    1996-03-01

    Results obtained in the NSRR power burst experiments with irradiated PWR fuel rods with fuel burnup up to 50 MWd/kgU are described and discussed in this paper. Data concerning test method, test fuel rod, pulse irradiation, transient records during the pulse and post irradiation examination are described, and interpretations and discussions on fission gas release and fuel pellet fragmentation are presented. During the pulse-irradiation experiment with 50 MWd/kgU PWR fuel rod, the fuel rod failed at considerably low energy deposition level, and large amount of fission gas release and fragmentation of fuel pellets were observed.

  16. Computer Programming: Fail Fast to Learn Sooner

    NASA Astrophysics Data System (ADS)

    Brito, Miguel A.; de Sá-Soares, Filipe

    Computer programming is not only to know about the languages or the processes, it is essentially to know how to do it. This involves a constructivist approach in learning. For a newbie in computer programming it is hard to understand the difference between know-about disciplines and the know-how-to-do-it ones. This leads to failure because when they understand they aren't able to solve a programming problem it is usually too late to catch all the time meanwhile lost. Our solution is to get them to fail soon enough. This way they still have time to recover from an eventually bad start.

  17. The evaluation of the failed shoulder arthroplasty.

    PubMed

    Wiater, Brett P; Moravek, James E; Wiater, J Michael

    2014-05-01

    As the incidence of shoulder arthroplasty continues to rise, the orthopedic shoulder surgeon will be increasingly faced with the difficult problem of evaluating a failed shoulder arthroplasty. The patient is usually dissatisfied with the outcome of the previous arthroplasty as a result of pain, but may complain of poor function due to limited range of motion or instability. A thorough and systematic approach is necessary so that the most appropriate treatment pathway can be initiated. A comprehensive history and physical examination are the first steps in the evaluation. Diagnostic studies are numerous and include laboratory values, plain radiography, computed tomography, ultrasound imaging, joint aspiration, nuclear scans, and electromyography. Common causes of early pain after shoulder arthroplasty include technical issues related to the surgery, such as malposition or improper sizing of the prosthesis, periprosthetic infection, neurologic injury, and complex regional pain syndrome. Pain presenting after a symptom-free interval may be related to chronic periprosthetic infection, component wear and loosening, glenoid erosion, rotator cuff degeneration, and fracture. Poor range of motion may result from inadequate postoperative rehabilitation, implant-related factors, and heterotopic ossification. Instability is generally caused by rotator cuff deficiency and implant-related factors. Unfortunately, determining the cause of a failed shoulder arthroplasty can be difficult, and in many situations, the source of pain and disability is multifactorial.

  18. What do we do after an implant fails? A review of treatment alternatives for failed implants.

    PubMed

    Machtei, Eli E

    2013-01-01

    The problem of failed implants cannot be overlooked. The purpose of this paper is to explore treatment alternatives for failed implants and their strengths and shortcomings. A comprehensive literature search was performed using PubMed and a manual search. Only five studies were identified that explored treatment in sites where implants had failed. In all five studies, the treatment alternative tested was the placement of a new implant in the failed site. The overall survival rate for such implants ranged from 71% to 92.3%. Four other alternatives are also discussed in light of data derived from other studies on the survival of various treatment strategies. These include: a continuation of the original plan using the remaining implants, modification of treatment to a tooth-supported fixed partial denture (FPD) or to a hybrid tooth-implant? supported FPD, or modification to a removable prosthesis. The selection of an appropriate alternative for failed implants is complex and involves biologic, mechanical, and psychologic considerations along with financial aspects. This should be a team decision with the patient's opinion included.

  19. A Solution to ``Too Big to Fail''

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-10-01

    Its a tricky business to reconcile simulations of our galaxys formation with our current observations of the Milky Way and its satellites. In a recent study, scientists have addressed one discrepancy between simulations and observations: the so-called to big to fail problem.From Missing Satellites to Too Big to FailThe favored model of the universe is the lambda-cold-dark-matter (CDM) cosmological model. This model does a great job of correctly predicting the large-scale structure of the universe, but there are still a few problems with it on smaller scales.Hubble image of UGC 5497, a dwarf galaxy associated with Messier 81. In the missing satellite problem, simulations of galaxy formation predict that there should be more such satellite galaxies than we observe. [ESA/NASA]The first is the missing satellites problem: CDM cosmology predicts that galaxies like the Milky Way should have significantly more satellite galaxies than we observe. A proposed solution to this problem is the argument that there may exist many more satellites than weve observed, but these dwarf galaxies have had their stars stripped from them during tidal interactions which prevents us from being able to see them.This solution creates a new problem, though: the too big to fail problem. This problem states that many of the satellites predicted by CDM cosmology are simply so massive that theres no way they couldnt have visible stars. Another way of looking at it: the observed satellites of the Milky Way are not massive enough to be consistent with predictions from CDM.Artists illustration of a supernova, a type of stellar feedback that can modify the dark-matter distribution of a satellite galaxy. [NASA/CXC/M. Weiss]Density Profiles and Tidal StirringLed by Mihai Tomozeiu (University of Zurich), a team of scientists has published a study in which they propose a solution to the too big to fail problem. By running detailed cosmological zoom simulations of our galaxys formation, Tomozeiu and

  20. Asymmetric Type Ia Supernovae from Detonating Failed Deflagrations

    NASA Astrophysics Data System (ADS)

    Plewa, T.; Kasen, D.; Brown, E. F.

    2005-05-01

    Despite four decades of vigorous research and substantial progress made in studying thermonuclear supernovae, the origins and nature of these objects remain a mystery. From a modeler's point of view, Type Ia supernovae are one of the most demanding and complex supercomputer applications. The final stages of their lives involve the slow evolution under conditions close to a hydrostatic equilibrium followed by a strongly dynamical phase with the possible transition from a subsonic to supersonic mode of thermonuclear combustion. The explosion dynamics involve instabilities on scales from centimeters to hundreds of kilometers, and are accompanied by thermonuclear reactions releasing sufficient energy to unbind the white dwarf. Numerical models of thermonuclear supernovae must also include realistic initial conditions, an element that may prove crucial in our quest to explain the nature of those fascinating objects. We are presently studying the incineration of a massive white dwarf following the mild ignition of a thermonuclear flame close to the stellar center. In this scenario, the initial off-center deflagration only consumes a small amount of the stellar fuel and fails to unbind the star. This deflagration does, however, expand the stellar material and accelerates the outer layers of the white dwarf. These flows interact and then trigger a detonation. The overall evolution resembles that of the previously discussed gravitationally confined detonation model and shares many of its properties. The present numerical model features a revised energy delivery scheme resulting in a weaker deflagration, longer evolutionary timescales, and stronger preexpansion of the stellar material.

  1. When continuous positive airway pressure (CPAP) fails

    PubMed Central

    Virk, Jagdeep S.

    2016-01-01

    Obstructive sleep apnoea (OSA) is increasingly prevalent, particularly in the context of the obesity epidemic, and is associated with a significant social, health and economic impact. The gold standard of treatment for moderate to severe OSA is continuous positive airway pressure (CPAP). However compliance rates can be low. Methodology to improve patient tolerance to CPAP alongside with alternative, non-surgical and surgical, management strategies are discussed. All patients that fail CPAP therapy would benefit from formal upper airway evaluation by the otolaryngologist to identify any obvious causes and consider site-specific surgical therapies. Patient selection is integral to ensuring successful outcomes. A multidisciplinary team is needed to manage these patients. PMID:27867577

  2. Terrestrial-passage theory: failing a test.

    PubMed

    Reed, Charles F; Krupinski, Elizabeth A

    2009-01-01

    Terrestrial-passage theory proposes that the 'moon' and 'sky' illusions occur because observers learn to expect an elevation-dependent transformation of visual angle. The transformation accompanies daily movement through ordinary environments of fixed-altitude objects. Celestial objects display the same visual angle at all elevations, and hence are necessarily non-conforming with the ordinary transformation. On hypothesis, observers should target angular sizes to appear greater at elevation than at horizon. However, in a sample of forty-eight observers there was no significant difference between the perceived angular size of a constellation of stars at horizon and that predicted for a specific elevation. Occurrence of the illusion was not restricted to those observers who expected angular expansion. These findings fail to support the terrestrial-passage theory of the illusion.

  3. Fail-over file transfer process

    NASA Technical Reports Server (NTRS)

    Semancik, Susan K. (Inventor); Conger, Annette M. (Inventor)

    2005-01-01

    The present invention provides a fail-over file transfer process to handle data file transfer when the transfer is unsuccessful in order to avoid unnecessary network congestion and enhance reliability in an automated data file transfer system. If a file cannot be delivered after attempting to send the file to a receiver up to a preset number of times, and the receiver has indicated the availability of other backup receiving locations, then the file delivery is automatically attempted to one of the backup receiving locations up to the preset number of times. Failure of the file transfer to one of the backup receiving locations results in a failure notification being sent to the receiver, and the receiver may retrieve the file from the location indicated in the failure notification when ready.

  4. Revision of Failed Artroscopic Bankart Repairs

    PubMed Central

    Muiño, José María Silberberg; Gimenez, Martín Alejandro; Salvucci, Mauro Gabriel Maroa; Ferro, Diego; Rullan, Ramón Muiña

    2017-01-01

    Objectives: To present our functional outcomes from patients treated arthroscopically for a failed Bankart repair, using suture anchors and capsulolabral tissue only. Methods: Series of 22 patients presented with a recurrence of instability after a previous stabilization surgery (3 Latarjet, Bankart 19). We treated them by a an all-arthroscopic procedure, avoiding bone grafts, when glenoid track was found to be enough to proceed. The failure was associated with trauma in 11 patients, a non-anatomic repair in 6 patients, capsular laxity in 4 patients and a non-union of the coracoid graft in 1 patient. Revision surgery included: Bankart repair with anchors in 17 cases, a posterior-inferior capsulo-labral plication in one case, and 5 remplissages. In 4 cases subscapularis augmentation was used because of poor capsular quality. Screw removal was necessary when treating the non-union case. Patients were followed-up by a minimum of 23 months (range 23-26), and evaluated by the UCLA Test, SS test and Rowe score. Results: Thirteen patients had an excellent result, 6 good, 2 satisfactory and one bad result, according to UCLA score. The mean Rowe score was 90.4, at final follow up. The Simple Shoulder Test went from an 8 preoperative to an 11 postoperative, mean scores. 19 of 22 patients returned to the same level of activity prior to the injury. Complications: recurrence in 2 cases, subluxation in 2 and one shoulder stiffness that required an arthrolysis. Conclusion: An arthroscopic revision surgery, after a failed Bankart repair, presents satisfactory results in selected patients. Arthroscopic vision allows a correct diagnosis of injuries as possible causes of failure and subsequent treatment.

  5. Synthetic Fuel

    ScienceCinema

    Idaho National Laboratory - Steve Herring, Jim O'Brien, Carl Stoots

    2016-07-12

    Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhouse gass Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhous

  6. Synthetic Fuel

    SciTech Connect

    Idaho National Laboratory - Steve Herring, Jim O'Brien, Carl Stoots

    2008-03-26

    Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhouse gass Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhous

  7. Fuel cells

    NASA Astrophysics Data System (ADS)

    1984-12-01

    The US Department of Energy (DOE), Office of Fossil Energy, has supported and managed a fuel cell research and development (R and D) program since 1976. Responsibility for implementing DOE's fuel cell program, which includes activities related to both fuel cells and fuel cell systems, has been assigned to the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. The total United States effort of the private and public sectors in developing fuel cell technology is referred to as the National Fuel Cell Program (NFCP). The goal of the NFCP is to develop fuel cell power plants for base-load and dispersed electric utility systems, industrial cogeneration, and on-site applications. To achieve this goal, the fuel cell developers, electric and gas utilities, research institutes, and Government agencies are working together. Four organized groups are coordinating the diversified activities of the NFCP. The status of the overall program is reviewed in detail.

  8. Future Fuels

    DTIC Science & Technology

    2005-10-04

    tactical ground mobility and increasing operational reach • Identify, review, and assess – Technologies for reducing fuel consumption, including...T I O N S A C T I O N S TOR Focus - Tactical ground mobility - Operational reach - Not A/C, Ships, or troops Hybrid Electric Vehicle Fuel Management...Fuel Management During Combat Operations Energy Fundamentals • Energy Density • Tactical Mobility • Petroleum Use • Fuel Usage (TWV) • TWV OP TEMPO TOR

  9. Proteomic analysis of membrane microdomains derived from both failing and non-failing human hearts.

    PubMed

    Banfi, Cristina; Brioschi, Maura; Wait, Robin; Begum, Shajna; Gianazza, Elisabetta; Fratto, Pasquale; Polvani, Gianluca; Vitali, Ettore; Parolari, Alessandro; Mussoni, Luciana; Tremoli, Elena

    2006-03-01

    Eukaryotic cells plasma membranes are organized into microdomains of specialized function such as lipid rafts and caveolae, with a specific lipid composition highly enriched in cholesterol and glycosphingolipids. In addition to their role in regulating signal transduction, multiple functions have been proposed, such as anchorage of receptors, trafficking of cholesterol, and regulation of permeability. However, an extensive understanding of their protein composition in human heart, both in failing and non-failing conditions, is not yet available. Membrane microdomains were isolated from left ventricular tissue of both failing (n = 15) and non-failing (n = 15) human hearts. Protein composition and differential protein expression was explored by comparing series of 2-D maps and subsequent identification by LC-MS/MS analysis. Data indicated that heart membrane microdomains are enriched in chaperones, cytoskeletal-associated proteins, enzymes and protein involved in signal transduction pathway. In addition, differential protein expression profile revealed that 30 proteins were specifically up- or down-regulated in human heart failure membrane microdomains. This study resulted in the identification of human heart membrane microdomain protein composition, which was not previously available. Moreover, it allowed the identification of multiple proteins whose expression is altered in heart failure, thus opening new perspectives to determine which role they may play in this disease.

  10. Fossil Fuels.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  11. Monitoring arrangement for vented nuclear fuel elements

    DOEpatents

    Campana, Robert J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180.degree. rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements.

  12. Fuel-in-air FY07 summary report

    SciTech Connect

    Hanson, Brady D.; Daniel, Richard C.; Casella, Andy M.; Wittman, Richard S.; Wu, Wesley; MacFarlan, Paul J.; Shimskey, Rick W.

    2008-01-22

    Results of the testing program to determine fractional release rates and particle size distributions from failed commercial spent fuel related to the operations in the surface facility at Yucca Mountain are presented.

  13. Alternative fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.; Butze, H. F.; Friedman, R.; Antoine, A. C.; Reynolds, T. W.

    1977-01-01

    Potential problems related to the use of alternative aviation turbine fuels are discussed and both ongoing and required research into these fuels is described. This discussion is limited to aviation turbine fuels composed of liquid hydrocarbons. The advantages and disadvantages of the various solutions to the problems are summarized. The first solution is to continue to develop the necessary technology at the refinery to produce specification jet fuels regardless of the crude source. The second solution is to minimize energy consumption at the refinery and keep fuel costs down by relaxing specifications.

  14. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  15. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  16. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  17. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Failed lots/rework procedure. 983.52 Section 983.52..., ARIZONA, AND NEW MEXICO Regulations § 983.52 Failed lots/rework procedure. (a) Substandard pistachios... committee may establish, with the Secretary's approval, appropriate rework procedures. (b) Failed...

  18. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  19. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  20. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  1. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  2. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  3. Rescuing failed oral implants via Wnt activation

    PubMed Central

    Yin, Xing; Li, Jingtao; Chen, Tao; Mouraret, Sylvain; Dhamdhere, Girija; Brunski, John B.; Zou, Shujuan; Helms, Jill A.

    2016-01-01

    Aim Implant osseointegration is not always guaranteed and once fibrous encapsulation occurs clinicians have few options other than implant removal. Our goal was to test whether a WNT protein therapeutic could rescue such failed implants. Material and Methods Titanium implants were placed in over-sized murine oral osteotomies. A lack of primary stability was verified by mechanical testing. Interfacial strains were estimated by finite element modelling and histology coupled with histomorphometry confirmed the lack of peri-implant bone. After fibrous encapsulation was established peri-implant injections of a liposomal formulation of WNT3A protein (L-WNT3A) or liposomal PBS (L-PBS) were then initiated. Quantitative assays were employed to analyse the effects of L-WNT3A treatment. Results Implants in gap-type interfaces exhibited high interfacial strains and no primary stability. After verification of implant failure, L-WNT3A or L-PBS injections were initiated. L-WNT3A induced a rapid, significant increase in Wnt responsiveness in the peri-implant environment, cell proliferation and osteogenic protein expression. The amount of peri-implant bone and bone in contact with the implant were significantly higher in L-WNT3A cases. Conclusions These data demonstrate L-WNT3A can induce peri-implant bone formation even in cases where fibrous encapsulation predominates. PMID:26718012

  4. Cognitive emotion regulation fails the stress test

    PubMed Central

    Raio, Candace M.; Orederu, Temidayo A.; Palazzolo, Laura; Shurick, Ashley A.; Phelps, Elizabeth A.

    2013-01-01

    Cognitive emotion regulation has been widely shown in the laboratory to be an effective way to alter the nature of emotional responses. Despite its success in experimental contexts, however, we often fail to use these strategies in everyday life where stress is pervasive. The successful execution of cognitive regulation relies on intact executive functioning and engagement of the prefrontal cortex, both of which are rapidly impaired by the deleterious effects of stress. Because it is specifically under stressful conditions that we may benefit most from such deliberate forms of emotion regulation, we tested the efficacy of cognitive regulation after stress exposure. Participants first underwent fear-conditioning, where they learned that one stimulus (CS+) predicted an aversive outcome but another predicted a neutral outcome (CS−). Cognitive regulation training directly followed where participants were taught to regulate fear responses to the aversive stimulus. The next day, participants underwent an acute stress induction or a control task before repeating the fear-conditioning task using these newly acquired regulation skills. Skin conductance served as an index of fear arousal, and salivary α-amylase and cortisol concentrations were assayed as neuroendocrine markers of stress response. Although groups showed no differences in fear arousal during initial fear learning, nonstressed participants demonstrated robust fear reduction following regulation training, whereas stressed participants showed no such reduction. Our results suggest that stress markedly impairs the cognitive regulation of emotion and highlights critical limitations of this technique to control affective responses under stress. PMID:23980142

  5. Capital disadvantage: America's failing capital investment system.

    PubMed

    Porter, M E

    1992-01-01

    The U.S. system of allocating investment capital is failing, putting American companies at a serious disadvantage and threatening the long-term growth of the nation's economy. The problem, says Michael Porter, goes beyond the usual formulation of the issue: accusations of "short-termism" by U.S. managers, ineffective corporate governance by directors, or a high cost of capital. The problem involves the external capital allocation system by which capital is provided to companies, as well as the system by which companies allocate capital internally. America's system is marked by fluid capital and a financial focus. Other countries--notably Japan and Germany--have systems with dedicated capital and a focus on corporate position. In global competition, where investment increasingly determines a company's capacity to upgrade and innovate, the U.S. system does not measure up. These conclusions come out of a two-year research project sponsored by the Harvard Business School and the Council on Competitiveness. Porter recommends five far-reaching reforms to make the U.S. system superior to Japan's and Germany's: 1. Improve the present macroeconomic environment. 2. Expand true ownership throughout the system so that directors, managers, employees, and even customers and suppliers hold positions as owners. 3. Align the goals of capital providers, corporations, directors, managers, employees, customers, suppliers, and society. 4. Improve the information used in decision making. 5. Foster more productive modes of interaction and influence among capital providers, corporations, and business units.

  6. 46 CFR 154.706 - Cargo boil-off as fuel: Fuel lines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... atmospheric pressure. Continuous gas detection must be installed to detect leaks in the ventilated space. The... Equipment Cargo Pressure and Temperature Control § 154.706 Cargo boil-off as fuel: Fuel lines. (a) Gas fuel... must be a double-walled piping system with the annular space containing an inert gas at a...

  7. 46 CFR 154.706 - Cargo boil-off as fuel: Fuel lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... atmospheric pressure. Continuous gas detection must be installed to detect leaks in the ventilated space. The... Equipment Cargo Pressure and Temperature Control § 154.706 Cargo boil-off as fuel: Fuel lines. (a) Gas fuel... must be a double-walled piping system with the annular space containing an inert gas at a...

  8. 46 CFR 154.706 - Cargo boil-off as fuel: Fuel lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... atmospheric pressure. Continuous gas detection must be installed to detect leaks in the ventilated space. The... Equipment Cargo Pressure and Temperature Control § 154.706 Cargo boil-off as fuel: Fuel lines. (a) Gas fuel... must be a double-walled piping system with the annular space containing an inert gas at a...

  9. 46 CFR 154.706 - Cargo boil-off as fuel: Fuel lines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... atmospheric pressure. Continuous gas detection must be installed to detect leaks in the ventilated space. The... Equipment Cargo Pressure and Temperature Control § 154.706 Cargo boil-off as fuel: Fuel lines. (a) Gas fuel... must be a double-walled piping system with the annular space containing an inert gas at a...

  10. 46 CFR 154.706 - Cargo boil-off as fuel: Fuel lines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... atmospheric pressure. Continuous gas detection must be installed to detect leaks in the ventilated space. The... Equipment Cargo Pressure and Temperature Control § 154.706 Cargo boil-off as fuel: Fuel lines. (a) Gas fuel... must be a double-walled piping system with the annular space containing an inert gas at a...

  11. Evaluation of ANF fuel failures in oyster creek

    SciTech Connect

    Howe, T.M.; Van Swam, L.F.; Piascik, T.G.; Spence, P.A.

    1988-01-01

    During the refueling outrage following cycle-10 operations of Oyster Creek nuclear generating station, fuel sipping identified 47 failed Advance Nuclear Fuels (ANF) fuel assemblies. The failed fuel was an unpressurized 8 x 8 design manufactured by ANF prior to 1980. Subsequent inspection of 46 of these 47 assemblies with the ANF ULTRATEST ultrasonic testing system indicated 104 either failed of suspect fuel rods in 44 assemblies. Two of the assemblies were identified as being sound. Selected fuel rods were removed from three of the assemblies and inspected both visually and with an eddycurrent coil. An evaluation has been performed to determine the cause of the failures. The failures were primarily the result of pellet/cladding interaction (PCI). Detailed analyses of several of the failed fuel rods were performed with ANF's fuel rod modeling code RAMPX2. RAMPX2 includes several state-of-the-art models, including a model describing the formation of fission product deposits called coins on the inside surface of the cladding, a model that accounts for axial PCI, and a trapped fuel stack model. The analyses provided an explanation for the failures.

  12. The effect of fuel rod oxidation on PCMI-induced fuel failure

    NASA Astrophysics Data System (ADS)

    Kim, Kyu-Tae

    2011-11-01

    It was found in a one of the PWRs operating in Korea that a few three cycle-burned Zry-4 fuel assemblies which were loaded in a core center region at control bank positions were leaking. The leaking cycle has experienced a few reactor trips and some fuel rods started to leak at about a month after a power ramp following the second reactor trip. To investigate a root cause of such fuel failure as well as to examine intact and leak rod oxidation behaviors, one intact and one leaking fuel rods were selected from one intact and one failed three cycle-burned fuel assemblies, respectively, and in parallel one intact fuel rod was selected from a two cycle-burned fuel assembly to examine the effect of burnup on fuel rod oxidation and cladding stress during the power ramp. The maximum oxide thicknesses for the intact two cycle-burned and three cycle-burned fuel rods were measured to be about 70 and 140 μm, respectively, whereas that for the leaking three cycle-burned fuel rod to be about 200 μm. The leaking fuel rods generated a very sharp increase in oxide thickness in the fuel rod upper region having a relatively high axial power, resulting in through-wall axial cracks. The root cause of the fuel rod leaks was evaluated to be the pellet-clad mechanical interaction (PCMI)-induced failure combined with excessive Zry-4 oxidation and cladding stress, based on the evaluations of pellet-clad friction coefficient-dependent cladding hoop stresses after the power ramp following the second trip, measured oxide thicknesses and axial cracks on the cladding surface, a fuel leak initiation time and failed fuel rod locations at the control bank positions.

  13. Myocardial regeneration of the failing heart.

    PubMed

    Akhmedov, Alexander T; Marín-García, José

    2013-11-01

    Human heart failure (HF) is one of the leading causes of morbidity and mortality worldwide. Currently, heart transplantation and implantation of mechanical devices represent the only available treatments for advanced HF. Two alternative strategies have emerged to treat patients with HF. One approach relies on transplantation of exogenous stem cells (SCs) of non-cardiac or cardiac origin to induce cardiac regeneration and improve ventricular function. Another complementary strategy relies on stimulation of the endogenous regenerative capacity of uninjured cardiac progenitor cells to rebuild cardiac muscle and restore ventricular function. Various SC types and delivery strategies have been examined in the experimental and clinical settings; however, neither the ideal cell type nor the cell delivery method for cardiac cell therapy has yet emerged. Although the use of bone marrow (BM)-derived cells, most frequently exploited in clinical trials, appears to be safe, the results are controversial. Two recent randomized trials have failed to document any beneficial effects of intracardiac delivery of autologous BM mononuclear cells on cardiac function of patients with HF. The remarkable discovery that various populations of cardiac progenitor cells (CPCs) are present in the adult human heart and that it possesses limited regeneration capacity has opened a new era in cardiac repair. Importantly, unlike BM-derived SCs, autologous CPCs from myocardial biopsies cultured and subsequently delivered by coronary injection to patients have given positive results. Although these data are promising, a better understanding of how to control proliferation and differentiation of CPCs, to enhance their recruitment and survival, is required before CPCs become clinically applicable therapeutics.

  14. Revision of failed humeral head resurfacing arthroplasty

    PubMed Central

    Streubel, Philipp N.; Simone, Juan P.; Cofield, Robert H.; Sperling, John W.

    2016-01-01

    Purpose: The purpose of this study is to assess the outcomes of a consecutive series of patients who underwent revision surgery after humeral head resurfacing (HHR). Our joint registry was queried for all patients who underwent revision arthroplasty for failed HHR at our institution from 2005 to 2010. Eleven consecutive patients (average age 54 years; range 38-69 years) that underwent revision of 11 resurfacing arthroplasties were identified. The primary indication for resurfacing had been osteoarthritis in six, glenoid dysplasia in two, a chondral lesion in two, and postinstability arthropathy in one patient. The indication for revision was pain in 10 and infection in one patient. Seven patients had undergone an average of 1.9 surgeries prior to resurfacing (range 1-3). Materials and Methods: All patients were revised to stemmed arthroplasties, including one hemiarthroplasty, two reverse, and eight anatomic total shoulder arthroplasties at a mean 33 months after primary resurfacing (range 10-131 months). A deltopectoral approach was used in seven patients; four patients required an anteromedial approach due to severe scarring. Subscapularis attenuation was found in four cases, two of which required reverse total shoulder arthroplasty. Bone grafting was required in one glenoid and three humeri. Results: At a mean follow-up of 3.5 years (range 1.6-6.9 years), modified Neer score was rated as satisfactory in five patients and unsatisfactory in six. Abduction and external rotation improved from 73° to 88° (P = 0.32) and from 23° to 32° (P = 0.28) respectively. Reoperation was required in two patients, including one hematoma and one revision for instability. Conclusion: Outcomes of revision of HHR arthroplasty in this cohort did not improve upon those reported for revision of stemmed humeral implants. A comparative study would be required to allow for definitive conclusions to be made. PMID:26980986

  15. Partial least squares analysis of rocket propulsion fuel data using diaphragm valve-based comprehensive two-dimensional gas chromatography coupled with flame ionization detection.

    PubMed

    Freye, Chris E; Fitz, Brian D; Billingsley, Matthew C; Synovec, Robert E

    2016-06-01

    The chemical composition and several physical properties of RP-1 fuels were studied using comprehensive two-dimensional (2D) gas chromatography (GC×GC) coupled with flame ionization detection (FID). A "reversed column" GC×GC configuration was implemented with a RTX-wax column on the first dimension ((1)D), and a RTX-1 as the second dimension ((2)D). Modulation was achieved using a high temperature diaphragm valve mounted directly in the oven. Using leave-one-out cross-validation (LOOCV), the summed GC×GC-FID signal of three compound-class selective 2D regions (alkanes, cycloalkanes, and aromatics) was regressed against previously measured ASTM derived values for these compound classes, yielding root mean square errors of cross validation (RMSECV) of 0.855, 0.734, and 0.530mass%, respectively. For comparison, using partial least squares (PLS) analysis with LOOCV, the GC×GC-FID signal of the entire 2D separations was regressed against the same ASTM values, yielding a linear trend for the three compound classes (alkanes, cycloalkanes, and aromatics), yielding RMSECV values of 1.52, 2.76, and 0.945 mass%, respectively. Additionally, a more detailed PLS analysis was undertaken of the compounds classes (n-alkanes, iso-alkanes, mono-, di-, and tri-cycloalkanes, and aromatics), and of physical properties previously determined by ASTM methods (such as net heat of combustion, hydrogen content, density, kinematic viscosity, sustained boiling temperature and vapor rise temperature). Results from these PLS studies using the relatively simple to use and inexpensive GC×GC-FID instrumental platform are compared to previously reported results using the GC×GC-TOFMS instrumental platform.

  16. Automated Fuel Element Closure Welding System

    SciTech Connect

    Wahlquist, D.R.

    1993-01-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

  17. Automated Fuel Element Closure Welding System

    SciTech Connect

    Wahlquist, D.R.

    1993-03-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

  18. Fuel compositions

    SciTech Connect

    Zaweski, E.F.; Niebylski, L.M.

    1986-08-05

    This patent describes distillate fuel for indirect injection compression ignition engines containing, in an amount sufficient to minimize coking, especially throttling nozzle coking in the prechambers or swirl chambers of indirect injection compression ignition engines operated on such fuel, at least the combination of (i) organic nitrate ignition accelerator and (ii) an esterified cycle dehydration product of sorbitol which, when added to the fuel in combination with the organic nitrate ignition accelerator minimizes the coking.

  19. Conditions inside Water Pooled in a Failed Nuclear Waste Container and its Effect on Radionuclide Release

    NASA Astrophysics Data System (ADS)

    Hamdan, L. K.; Walton, J. C.; Woocay, A.

    2009-12-01

    Nuclear power use is expected to expand in the future, as part of the global clean energy initiative, to meet the world’s surging energy demand, and attenuate greenhouse gas emissions, which are mainly caused by fossil fuels. As a result, it is estimated that hundreds of thousands of metric tons of spent nuclear fuel (SNF) will accumulate. SNF disposal has major environmental (radiation exposure) and security (nuclear proliferation) concerns. Storage in unsaturated zone geological repositories is a reasonable solution for dealing with SNF. One of the key factors that determine the performance of the geological repository is the release of radionuclides from the engineered barrier system. Over time, the nuclear waste containers are expected to fail gradually due to general and localized corrosions and eventually infiltrating water will have access to the nuclear waste. Once radionuclides are released, they will be transported by water, and make their way to the accessible environment. Physical and chemical disturbances in the environment over the container will lead to different corrosion rates, causing different times and locations of penetration. One possible scenario for waste packages failure is the bathtub model, where penetrations occur on the top of the waste package and water pools inside it. In this paper the bathtub-type failed waste container is considered. We shed some light on chemical and physical processes that take place in the pooled water inside a partially failed waste container (bathtub category), and the effects of these processes on radionuclide release. Our study considers two possibilities: temperature stratification of the pooled water versus mixing process. Our calculations show that temperature stratification of the pooled water is expected when the waste package is half (or less) filled with water. On the other hand, when the waste package is fully filled (or above half) there will be mixing in the upper part of water. The effect of

  20. Fuel cells 101

    SciTech Connect

    Hirschenhofer, J.H.

    1999-07-01

    This paper discusses the various types of fuel cells, the importance of cell voltage, fuel processing for natural gas, cell stacking, fuel cell plant description, advantages and disadvantages of the types of fuel cells, and applications. The types covered include: polymer electrolyte fuel cell, alkaline fuel cell, phosphoric acid fuel cell; molten carbonate fuel cell, and solid oxide fuel cell.

  1. Fuel dehazers

    SciTech Connect

    Lyons, W.R.

    1986-03-01

    Hazy fuels can be caused by the emulsification of water into the fuel during refining, blending, or transportation operations. Detergent additive packages used in gasoline tend to emulsify water into the fuel. Fuels containing water haze can cause corrosion and contamination, and support microbiological growth. This results in problems. As the result of these problems, refiners, marketers, and product pipeline companies customarily have haze specifications. The haze specification may be a specific maximum water content or simply ''bright and clear'' at a specified temperature.

  2. Motor fuel

    SciTech Connect

    Burns, L.D.

    1982-07-13

    Liquid hydrocarbon fuel compositions are provided containing antiknock quantities of ashless antiknock agents comprising selected furyl compounds including furfuryl alcohol, furfuryl amine, furfuryl esters, and alkyl furoates.

  3. Alternative fuels

    SciTech Connect

    Not Available

    1991-07-01

    This paper presents the preliminary results of a review, of the experiences of Brazil, Canada, and New Zealand, which have implemented programs to encourage the use of alternative motor fuels. It will also discuss the results of a separate completed review of the Department of Energy's (DOE) progress in implementing the Alternative Motor Fuels Act of 1988. The act calls for, among other things, the federal government to use alternative-fueled vehicles in its fleet. The Persian Gulf War, environmental concerns, and the administration's National Energy Strategy have greatly heightened interest in the use of alternative fuels in this country.

  4. Leptomeningeal rheumatoid nodules: diagnosis and failed therapeutics.

    PubMed

    Nesbitt, Cassie; Willshire, Luke; Quan, Doreen; Shaw, Cameron; Batchelor, Peter

    2015-02-01

    A 67-year-old woman presented with recurrent transient ischaemic attack-like episodes over a 2 year period. Nodular enhancing leptomeningeal changes were detected on MRI and were consistent with meningeal rheumatoid nodules on biopsy. The patient's nodular disease continued to progress and regress clinically and radiologically irrespective of disease modifying agents and peripheral and serological rheumatoid arthritis control. This patient's unique presentation and diagnostic work-up is discussed alongside the dilemma of therapeutic management of meningeal rheumatoid nodules.

  5. Interior's Climate Science Centers: Focus or Fail

    NASA Astrophysics Data System (ADS)

    Udall, B.

    2012-12-01

    After a whirlwind two years of impressive and critical infrastructure building, the Department of Interior's Climate Science Centers are now in a position to either succeed or fail. The CSCs have a number of difficult structural problems including too many constituencies relative to the available resources, an uneasy relationship among many of the constituencies including the DOI agencies themselves, a need to do science in a new, difficult and non-traditional way, and a short timeframe to produce useful products. The CSCs have built a broad and impressive network of scientists and stakeholders. These entities include science providers of the universities and the USGS, and decision makers from the states, tribes, DOI land managers and other federal agencies and NGOs. Rather than try to support all of these constituencies the CSCs would be better served by refocusing on a core mission of supporting DOI climate related decision making. The CSCs were designed to service the climate science needs of DOI agencies, many of which lost their scientific capabilities in the 1990s due to a well-intentioned but ultimately harmful re-organization at DOI involving the now defunct National Biological Survey. Many of these agencies would like to have their own scientists, have an uneasy relationship with the nominal DOI science provider, the USGS, and don't communicate effectively among themselves. The CSCs must not succumb to pursuing science in either the traditional mode of the USGS or in the traditional mode of the universities, or worse, both of them. These scientific partners will need to be flexible, learn how to collaborate and should expect to see fewer resources. Useful CSC processes and outputs should start with the recommendations of the 2009 NRC Report Informing Decisions in a Changing Climate: (1) begin with users' needs; (2) give priority to process over products; (3) link information producers and users; (4) build connections across disciplines and organizations

  6. Fuel injector

    DOEpatents

    Lambeth, Malcolm David Dick

    2001-02-27

    A fuel injector comprises first and second housing parts, the first housing part being located within a bore or recess formed in the second housing part, the housing parts defining therebetween an inlet chamber, a delivery chamber axially spaced from the inlet chamber, and a filtration flow path interconnecting the inlet and delivery chambers to remove particulate contaminants from the flow of fuel therebetween.

  7. Antimisting fuel breakup and flammability

    NASA Technical Reports Server (NTRS)

    Parikh, P.; Fleeter, R.; Sarohia, V.

    1983-01-01

    The breakup behavior and flammability of antimisting turbine fuels subjected to aerodynamic shear are investigated. Fuels tested were Jet A containing 0.3% FM-9 polymer at various levels of degradation ranging from virgin AMK to neat Jet A. The misting behavior of the fuels was quantified by droplet size distribution measurements. A technique based on high resolution laser photography and digital image processing of photographic records for rapid determination of droplet size distribution was developed. The flammability of flowing droplet-air mixtures was quantified by direct measurements of temperature rise in a flame established in the wake of a continuous ignition source. The temperature rise measurements were correlated with droplet size measurements. The flame anchoring phenomenon associated with the breakup of a liquid fuel in the wake of bluff body was shown to be important in the context of a survivable crash scenario. A pass/fail criterion for flammability testing of antimisting fuels, based on this flame-anchoring phenomenon, was proposed. The role of various ignition sources and their intensity in ignition and post-ignition behavior of antimisting fuels was also investigated.

  8. 1-stage primary arthroplasty of mechanically failed internally fixated of hip fractures with deep wound infection

    PubMed Central

    Klatte, Till O; O’Loughlin, Padraigh F; Citak, Mustafa; Rueger, Johannes M; Gehrke, Thorsten; Kendoff, Daniel

    2013-01-01

    Background and purpose Mechanically failed internal fixation following hip fracture is often treated by salvage arthroplasty. If deep wound infection is present, a 2-stage procedure is often used. We have used a 1-stage procedure in infected cases, and we now report the outcome. Patients and methods We reviewed 16 cases of deep wound infection after mechanically failed hip fracture fixation, treated between 1994 and 2010. In all patients, a joint prosthesis was implanted in a 1-stage procedure. Results After an average follow-up period of 12 (2–18) years, no reinfection was detected. In 4 cases, a hip dislocation occurred and 3 of these needed further surgery. Interpretation A 1-stage procedure for arthroplasty of an infected, mechanically failed hip fracture fixation is feasible and carries a low risk of infection. PMID:23799345

  9. Fuel cell-fuel cell hybrid system

    DOEpatents

    Geisbrecht, Rodney A.; Williams, Mark C.

    2003-09-23

    A device for converting chemical energy to electricity is provided, the device comprising a high temperature fuel cell with the ability for partially oxidizing and completely reforming fuel, and a low temperature fuel cell juxtaposed to said high temperature fuel cell so as to utilize remaining reformed fuel from the high temperature fuel cell. Also provided is a method for producing electricity comprising directing fuel to a first fuel cell, completely oxidizing a first portion of the fuel and partially oxidizing a second portion of the fuel, directing the second fuel portion to a second fuel cell, allowing the first fuel cell to utilize the first portion of the fuel to produce electricity; and allowing the second fuel cell to utilize the second portion of the fuel to produce electricity.

  10. Fuels research: Fuel thermal stability overview

    NASA Technical Reports Server (NTRS)

    Cohen, S. M.

    1980-01-01

    Alternative fuels or crude supplies are examined with respect to satisfying aviation fuel needs for the next 50 years. The thermal stability of potential future fuels is discussed and the effects of these characteristics on aircraft fuel systems are examined. Advanced fuel system technology and design guidelines for future fuels with lower thermal stability are reported.

  11. Solenoid-valve-controlled fuel injection device

    SciTech Connect

    Oshizawa, H.

    1988-12-06

    This patent describes a solenoid-valve-controlled fuel injection device comprising: a fuel injection pump having a pump cylinder, a plunger rotatably and reciprocably disposed in the pump cylinder in a fluid-tight manner and defining a fuel pressurization chamber between a distal end of the plunger and the pump cylinder, a drive shaft rotatable in synchronism with an output shaft of an internal combustion engine, means responsive to rotation of the drive shaft for reciprocably displacing the plunger to pressurize fuel in the pressurization chamber, and a fuel chamber for being supplied with fuel from a fuel tank in response to rotation of the drive shaft, whereby the pressurized fuel can be fed into cylinders of the internal combustion engine; a solenoid valve for selectively opening and closing a communication passage by which the pressurization chamber and the fuel chamber communicate with each other; valve opening delay time detecting means for detecting a valve opening delay time of the solenoid valve; valve closing delay time detecting means for detecting a valve closing delay time of the solenoid valve; valve closing period calculating means for calculating a valve closing time of the solenoid valve according to operating conditions of the internal combustion engine; target fuel injection time calculating means for calculating a target fuel injection time according to the operating conditions of the internal combustion engine.

  12. Hemodynamic Conditions in a Failing Peripheral Artery Bypass Graft

    PubMed Central

    McGah, Patrick M.; Leotta, Daniel F.; Beach, Kirk W.; Zierler, R. Eugene; Riley, James J.; Aliseda, Alberto

    2012-01-01

    Objective The mechanisms of restenosis in autogenous vein bypass grafts placed for peripheral artery disease are not completely understood. We seek to investigate the role of hemodynamic stress in a case study of a revised bypass graft that failed due to restenosis. Methods The morphology of the lumen is reconstructed from a custom 3D ultrasound system. Scans were taken at one, six, and sixteen months after a patch angioplasty procedure. Computational hemodynamic simulations of the patient-specific model provide the blood flow features and the hemodynamic stresses on the vessel wall at the three time points studied. Results The vessel was initially free of any detectable lesions, but a 60% diameter reducing stenosis developed over the 16 month interval of study. As determined from the simulations, chaotic and recirculating flow occurred downstream of the stenosis due to the sudden widening of the lumen at the patch location. Curvature and a sudden increase in the lumen cross-sectional area induce these flow features that are hypothesized to be conducive to intimal hyperplasia. Favorable agreement was found between simulation results and in vivo Doppler ultrasound velocity measurements. Conclusions Transitional and chaotic flow occurs at the site of the revision, inducing a complex pattern of wall shear are computed with the hemodynamic simulations. This supports the hypothesis that the hemodynamic stresses in the revised segment, produced by the coupling of vessel geometry and chaotic flow, led to the intimal hyperplasia and restenosis of the graft. PMID:22551907

  13. Fuel ethanol

    SciTech Connect

    Not Available

    1989-02-01

    This report discusses the Omnibus Trade and Competitiveness Act of 1988 which requires GAO to examine fuel ethanol imports from Central America and the Caribbean and their impact on the U.S. fuel ethanol industry. Ethanol is the alcohol in beverages, such as beer, wine, and whiskey. It can also be used as a fuel by blending with gasoline. It can be made from renewable resources, such as corn, wheat, grapes, and sugarcane, through a process of fermentation. This report finds that, given current sugar and gasoline prices, it is not economically feasible for Caribbean ethanol producers to meet the current local feedstock requirement.

  14. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Failed lots/rework procedure. 983.152 Section 983.152..., ARIZONA, AND NEW MEXICO Rules and Regulations § 983.152 Failed lots/rework procedure. (a) Inshell rework procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of...

  15. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  16. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  17. 75 FR 76321 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ78 Source of Income From Qualified Fails Charges AGENCY... Internal Revenue Code. These regulations set forth the source of income attributable to qualified fails... Subjects in 26 CFR Part 1 Income taxes, Reporting and recordkeeping requirements. Proposed Amendment to...

  18. 75 FR 76262 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ85 Source of Income From Qualified Fails Charges AGENCY... temporary regulations which set forth the source of income attributable to qualified fails charges. The.... source income of foreign persons that is not effectively connected with the conduct of a trade...

  19. 77 FR 9846 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ78 Source of Income From Qualified Fails Charges AGENCY.... SUMMARY: This document contains final regulations that prescribe the source of income received on a... income from a qualified fails charge is generally determined by reference to the residence of...

  20. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  1. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  2. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  3. Erika's Stories: Literacy Solutions for a Failing Middle School Student

    ERIC Educational Resources Information Center

    Ma'ayan, Hadar Dubowsky

    2010-01-01

    Erika was a failing student at a large urban public middle school. She was poor, Hispanic, bilingual, and had repeated fourth grade. She scored low on her standardized tests and was failing several subject areas. In class, Erika was a student who sat silently with her head on her desk, and rarely turned in any of her assignments. She was a…

  4. Method of preparing gas tags for identification of single and multiple failures of nuclear reactor fuel assemblies

    DOEpatents

    McCormick, Norman J.

    1976-01-01

    For use in the identification of failed fuel assemblies in a nuclear reactor, the ratios of the tag gas isotopic concentrations are located on curved surfaces to enable the ratios corresponding to failure of a single fuel assembly to be distinguished from those formed from any combination of two or more failed assemblies.

  5. Morbidity associated with failed vaginal birth after cesarean section.

    PubMed

    Oboro, Victor; Adewunmi, Adeniyi; Ande, Anibaba; Olagbuji, Biodun; Ezeanochie, Michael; Oyeniran, Ayodeji

    2010-09-01

    We investigated morbidity and factors associated with failed vaginal birth after cesarean delivery (VBAC). In a retrospective cohort study maternal and neonatal outcomes of women who underwent VBAC in three Nigerian University Teaching Hospitals were reviewed. Univariate, followed by multivariate analyses, were conducted. VBAC was successful in 683 of 1,013 women (67.4%), whereas 330 (32.6%) had failed VBAC. Failed VBAC was associated with higher incidence of chorioamnionitis, postpartum hemorrhage, blood transfusion, uterine rupture, hysterectomy, and composite major neonatal morbidities. Younger age, lack of previous vaginal delivery, induction of labor and fetal weight >4,000 g were risk factors for failed VBAC. A majority of women who try VBAC achieve a vaginal delivery. Failed VBAC is associated with increased maternal and neonatal morbidity and is somewhat predictable.

  6. IFR fuel cycle--pyroprocess development

    SciTech Connect

    Laidler, J.J.; Miller, W.E.; Johnson, T.R.; Ackerman, J.P.; Battles, J.E.

    1992-01-01

    The Integral Fast Reactor (IFR) fuel cycle is based on the use of a metallic fuel alloy, with nominal composition U-2OPu-lOZr. In its present state of development, this fuel system offers excellent high-burnup capabilities. Test fuel has been carried to burnups in excess of 20 atom % in EBR-II irradiations, and to peak burnups over 15 atom % in FFTF. The metallic fuel possesses physical characteristics, in particular very high thermal conductivity, that facilitate a high degree of passive inherent safety in the IFR design. The fuel has been shown to provide very large margins to failure in overpower transient events. Rapid overpower transient tests carried out in the TREAT reactor have shown the capability to withstand up to 400% overpower conditions before failing. An operational transient test conducted in EBR-II at a power ramp rate of 0.1% per second reached its termination point of 130% of normal power without any fuel failures. The IFR metallic fuel also exhibits superior compatibility with the liquid sodium coolant. Equally as important as the performance advantages offered by the use of metallic fuel is the fact that this fuel system permits the use of an innovative reprocessing method, known as pyroprocessing,'' featuring fused-salt electrorefining of the spent fuel. Development of the IFR pyroprocess has been underway at the Argonne National Laboratory for over five years, and great progress has been made toward establishing a commercially-viable process. Pyroprocessing offers a simple, compact means for closure of the fuel cycle, with anticipated significant savings in fuel cycle costs.

  7. IFR fuel cycle--pyroprocess development

    SciTech Connect

    Laidler, J.J.; Miller, W.E.; Johnson, T.R.; Ackerman, J.P.; Battles, J.E.

    1992-11-01

    The Integral Fast Reactor (IFR) fuel cycle is based on the use of a metallic fuel alloy, with nominal composition U-2OPu-lOZr. In its present state of development, this fuel system offers excellent high-burnup capabilities. Test fuel has been carried to burnups in excess of 20 atom % in EBR-II irradiations, and to peak burnups over 15 atom % in FFTF. The metallic fuel possesses physical characteristics, in particular very high thermal conductivity, that facilitate a high degree of passive inherent safety in the IFR design. The fuel has been shown to provide very large margins to failure in overpower transient events. Rapid overpower transient tests carried out in the TREAT reactor have shown the capability to withstand up to 400% overpower conditions before failing. An operational transient test conducted in EBR-II at a power ramp rate of 0.1% per second reached its termination point of 130% of normal power without any fuel failures. The IFR metallic fuel also exhibits superior compatibility with the liquid sodium coolant. Equally as important as the performance advantages offered by the use of metallic fuel is the fact that this fuel system permits the use of an innovative reprocessing method, known as ``pyroprocessing,`` featuring fused-salt electrorefining of the spent fuel. Development of the IFR pyroprocess has been underway at the Argonne National Laboratory for over five years, and great progress has been made toward establishing a commercially-viable process. Pyroprocessing offers a simple, compact means for closure of the fuel cycle, with anticipated significant savings in fuel cycle costs.

  8. Fission gas detection system

    DOEpatents

    Colburn, Richard P.

    1985-01-01

    A device for collecting fission gas released by a failed fuel rod which device uses a filter to pass coolant but which filter blocks fission gas bubbles which cannot pass through the filter due to the surface tension of the bubble.

  9. Earthquake recurrence models fail when earthquakes fail to reset the stress field

    USGS Publications Warehouse

    Tormann, Thessa; Wiemer, Stefan; Hardebeck, Jeanne L.

    2012-01-01

    Parkfield's regularly occurring M6 mainshocks, about every 25 years, have over two decades stoked seismologists' hopes to successfully predict an earthquake of significant size. However, with the longest known inter-event time of 38 years, the latest M6 in the series (28 Sep 2004) did not conform to any of the applied forecast models, questioning once more the predictability of earthquakes in general. Our study investigates the spatial pattern of b-values along the Parkfield segment through the seismic cycle and documents a stably stressed structure. The forecasted rate of M6 earthquakes based on Parkfield's microseismicity b-values corresponds well to observed rates. We interpret the observed b-value stability in terms of the evolution of the stress field in that area: the M6 Parkfield earthquakes do not fully unload the stress on the fault, explaining why time recurrent models fail. We present the 1989 M6.9 Loma Prieta earthquake as counter example, which did release a significant portion of the stress along its fault segment and yields a substantial change in b-values.

  10. Alternative jet aircraft fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1979-01-01

    Potential changes in jet aircraft fuel specifications due to shifts in supply and quality of refinery feedstocks are discussed with emphasis on the effects these changes would have on the performance and durability of aircraft engines and fuel systems. Combustion characteristics, fuel thermal stability, and fuel pumpability at low temperature are among the factors considered. Combustor and fuel system technology needs for broad specification fuels are reviewed including prevention of fuel system fouling and fuel system technology for fuels with higher freezing points.

  11. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, Bertrand D.; Confer, Gregory L.; Shen, Zujing; Hapeman, Martin J.; Flynn, Paul L.

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slutty, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure.

  12. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, B.D.; Confer, G.L.; Zujing Shen; Hapeman, M.J.; Flynn, P.L.

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slurry, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure. 19 figures.

  13. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, R.E.

    1988-03-08

    Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream 1 and spent fuel stream 2. Spent fuel stream 1 is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream 1 and exhaust stream 2, and exhaust stream 1 is vented. Exhaust stream 2 is mixed with spent fuel stream 2 to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells. 1 fig.

  14. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, Ralph E.

    1988-01-01

    Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream I and spent fuel stream II. Spent fuel stream I is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream I and exhaust stream II, and exhaust stream I is vented. Exhaust stream II is mixed with spent fuel stream II to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells.

  15. In Situ Optimal Reshading of Arrays with Failed Elements

    DTIC Science & Technology

    2016-06-13

    unlimited 13. SUPPLEMENTARY NOTES NUWC2015 14. ABSTRACT An algorithm is presented which computes optimal weights for arbitrary linear arrays. The...application of this algorithm to in situ optimal reshading of arrays with failed elements is discussed. It is shown that optimal reshading can often...which computes optimal weights for arbitrary linear arrays. The application of this algorithm to in situ optimal reshading of arrays with failed

  16. US Intervention in Failed States: Bad Assumptions=Poor Outcomes

    DTIC Science & Technology

    2002-01-01

    NATIONAL DEFENSE UNIVERSITY NATIONAL WAR COLLEGE STRATEGIC LOGIC ESSAY US INTERVENTION IN FAILED STATES: BAD ASSUMPTIONS = POOR ...2002 2. REPORT TYPE 3. DATES COVERED 00-00-2002 to 00-00-2002 4. TITLE AND SUBTITLE US Intervention in Failed States: Bad Assumptions= Poor ...country remains in the grip of poverty , natural disasters, and stagnation. Rwanda Rwanda, another small African country, is populated principally

  17. Laser explantation of a failing endosseous dental implant.

    PubMed

    Smith, L P; Rose, T

    2010-06-01

    Explantation of failed dental implants has traditionally been performed by mechanical bone removal techniques. The advent of intraoral laser surgery has seen increasing numbers of applications in oral implantology. The technique demonstrates safe and efficient explantation of a failed dental implant using Er,Cr:YSGG laser. Laser assisted explantation of dental implants is a minimally invasive technique providing an alternative to conventional mechanical explantation techniques.

  18. FUEL ELEMENT

    DOEpatents

    Fortescue, P.; Zumwalt, L.R.

    1961-11-28

    A fuel element was developed for a gas cooled nuclear reactor. The element is constructed in the form of a compacted fuel slug including carbides of fissionable material in some cases with a breeder material carbide and a moderator which slug is disposed in a canning jacket of relatively impermeable moderator material. Such canned fuel slugs are disposed in an elongated shell of moderator having greater gas permeability than the canning material wherefore application of reduced pressure to the space therebetween causes gas diffusing through the exterior shell to sweep fission products from the system. Integral fission product traps and/or exterior traps as well as a fission product monitoring system may be employed therewith. (AEC)

  19. Fuel bundle

    SciTech Connect

    Lui, C.K.

    1989-04-04

    This patent describes a method of forming a fuel bundle of a nuclear reactor. The method consists of positioning the fuel rods in the bottom plate, positioning the tie rod in the bottom plate with the key passed through the receptacle to the underside of the bottom plate and, after the tie rod is so positioned, turning the tie rod so that the key is in engagement with the underside of the bottom plate. Thereafter mounting the top plate is mounted in engagement with the fuel rods with the upper end of the tie rod extending through the opening in the top plate and extending above the top plate, and the tie rod is secured to the upper side of sid top plate thus simultaneously securing the key to the underside of the bottom plate.

  20. FUEL ELEMENT

    DOEpatents

    Howard, R.C.; Bokros, J.C.

    1962-03-01

    A fueled matrlx eontnwinlng uncomblned carbon is deslgned for use in graphlte-moderated gas-cooled reactors designed for operatlon at temperatures (about 1500 deg F) at which conventional metallic cladding would ordlnarily undergo undesired carburization or physical degeneratlon. - The invention comprlses, broadly a fuel body containlng uncombined earbon, clad with a nickel alloy contalning over about 28 percent by' weight copper in the preferred embodlment. Thls element ls supporirted in the passageways in close tolerance with the walls of unclad graphite moderator materlal. (AEC)

  1. Impact of Fuel Failure on Criticality Safety of Used Nuclear Fuel

    SciTech Connect

    Marshall, William BJ J; Wagner, John C

    2012-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for considerably longer periods than originally intended (e.g., <40 years). Extended storage (ES) time and irradiation of nuclear fuel to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, can result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. This effort is primarily motivated by concerns related to the potential for fuel degradation during ES periods and transportation following ES. The criticality analyses consider representative UNF designs and cask systems and a range of fuel enrichments, burnups, and cooling times. The various failed-fuel configurations considered are designed to bound the anticipated effects of individual rod and general cladding failure, fuel rod deformation, loss of neutron absorber materials, degradation of canister internals, and gross assembly failure. The results quantify the potential impact on criticality safety associated with fuel reconfiguration and may be used to guide future research, design, and regulatory activities. Although it can be concluded that the criticality safety impacts of fuel reconfiguration during transportation subsequent to ES are manageable, the results indicate that certain configurations can result in a large increase in the effective neutron multiplication factor, k{sub eff}. Future work to inform decision making relative to which configurations are credible, and therefore need to be considered in a safety evaluation, is recommended.

  2. Preliminary input to the space shuttle reaction control subsystem failure detection and identification software requirements (uncontrolled)

    NASA Technical Reports Server (NTRS)

    Bergmann, E.

    1976-01-01

    The current baseline method and software implementation of the space shuttle reaction control subsystem failure detection and identification (RCS FDI) system is presented. This algorithm is recommended for conclusion in the redundancy management (RM) module of the space shuttle guidance, navigation, and control system. Supporting software is presented, and recommended for inclusion in the system management (SM) and display and control (D&C) systems. RCS FDI uses data from sensors in the jets, in the manifold isolation valves, and in the RCS fuel and oxidizer storage tanks. A list of jet failures and fuel imbalance warnings is generated for use by the jet selection algorithm of the on-orbit and entry flight control systems, and to inform the crew and ground controllers of RCS failure status. Manifold isolation valve close commands are generated in the event of failed on or leaking jets to prevent loss of large quantities of RCS fuel.

  3. Posttest examination results of recent treat tests on metal fuel

    SciTech Connect

    Holland, J.W.; Wright, A.E.; Bauer, T.H.; Goldman, A.J.; Klickman, A.E.; Sevy, R.H.

    1986-01-01

    A series of in-reactor transient tests is underway to study the characteristics of metal-alloy fuel during transient-overpower-without-scam conditions. The initial tests focused on determining the margin to cladding breach and the axial fuel motions that would mitigate the power excursion. The tests were conducted in flowing-sodium loops with uranium - 5% fissium EBR-II Mark-II driver fuel elements in the TREAT facility. Posttest examination of the tests evaluated fuel elongation in intact pins and postfailure fuel motion. Microscopic examination of the intact pins studied the nature and extent of fuel/cladding interaction, fuel melt fraction and mass distribution, and distribution of porosity. Eutectic penetration and failure of the cladding were also examined in the failed pins.

  4. Fuel injection apparatus for internal combustion engines

    SciTech Connect

    Nozaki, S.; Yamada, K.; Kushida, T.

    1986-11-18

    This patent describes a fuel injection apparatus including a fuel injection pump which is adapted to carry out fuel intake, fuel pressurization, fuel injection and draining of cut-off fuel in accordance with the reciprocal movement of a plunger. The plunger is driven in synchronization with the rotational operation of an internal combustion engine. The apparatus comprises: a first storing means for temporarily storing cut-off fuel drained at the same time of the termination of the fuel injection; a second storing means of changeable volume for temporarily storing fuel for intake, the second storing means having a movable member which is movable in response to the quantity of fuel introduced therein; a detecting means for producing a detection signal relating to the amount of fuel stored in the second storing means; a clamping means responsible to an electric signal for clamping the movable member; and a signal producing means for producing at least one condition signal relating to the operating condition of the internal combustion engine.

  5. Shuttle Primary Reaction Control Subsystem Thruster Fuel Valve Pilot Seal Extrusion: A Failure Correlation

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Saulsberry, Regor L.

    2003-01-01

    Pilot operated valves (POVs) are used to control the flow of hypergolic propellants monomethylhydrazine (fuel) and nitrogen tetroxide (oxidizer) to the Shuttle orbiter Primary Reaction Control Subsystem (PRCS) thrusters. The POV incorporates a two-stage design: a solenoid-actuated pilot stage, which in turn controls a pressure-actuated main stage. Isolation of propellant supply from the thruster chamber is accomplished in part by a captive polytetrafluoroethylene (PTFE) pilot seal retained inside a Custom 455.1 stainless steel cavity. Extrusion of the pilot seal restricts the flow of fuel around the pilot poppet, thus impeding or preventing the main valve stage from opening. It can also prevent the main stage from staying open with adequate force margin, particularly if there is gas in the main stage actuation cavity. During thruster operation on-orbit, fuel valve pilot seal extrusion is commonly indicated by low or erratic chamber pressure or failure of the thruster to fire upon command (Fail-Off). During ground turnaround, pilot seal extrusion is commonly indicated by slow gaseous nitrogen (GN2) main valve opening times (greater than 38 ms) or slow water main valve opening response times (greater than 33 ms). Poppet lift tests and visual inspection can also detect pilot seal extrusion during ground servicing; however, direct metrology on the pilot seat assembly provides the most quantitative and accurate means of identifying extrusion. Minimizing PRCS fuel valve pilot seal extrusion has become an important issue in the effort to improve PRCS reliability and reduce associated life cycle costs.

  6. Solid Surface Combustion Experiment: Thick Fuel Results

    NASA Technical Reports Server (NTRS)

    Altenkirch, Robert A.; Bhattacharjee, Subrata; West, Jeff; Tang, Lin; Sacksteder, Kurt; Delichatsios, Michael A.

    1997-01-01

    The results of experiments for spread over polymethylmethacrylate, PMMA, samples in the microgravity environment of the Space Shuttle are described. The results are coupled with modelling in an effort to describe the physics of the spread process for thick fuels in a quiescent, microgravity environment and uncover differences between thin and thick fuels. A quenching phenomenon not present for thin fuels is delineated, namely the fact that for thick fuels the possibility exists that, absent an opposing flow of sufficient strength to press the flame close enough to the fuel surface to allow the heated layer in the solid to develop, the heated layer fails to become 'fully developed.' The result is that the flame slows, which in turn causes an increase in the relative radiative loss from the flame, leading eventually to extinction. This potential inability of a thick fuel to develop a steady spread rate is not present for a thin fuel because the heated layer is the fuel thickness, which reaches a uniform temperature across the thickness relatively rapidly.

  7. Nuclear Fuels.

    ERIC Educational Resources Information Center

    Nash, J. Thomas

    1983-01-01

    Trends in and factors related to the nuclear industry and nuclear fuel production are discussed. Topics addressed include nuclear reactors, survival of the U.S. uranium industry, production costs, budget cuts by the Department of Energy and U.S. Geological survey for resource studies, mining, and research/development activities. (JN)

  8. Fuel Cells

    ERIC Educational Resources Information Center

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  9. Future Fuel.

    ERIC Educational Resources Information Center

    Stover, Del

    1991-01-01

    Tough new environmental laws, coupled with fluctuating oil prices, are likely to prompt hundreds of school systems to examine alternative fuels. Literature reviews and interviews with 45 government, education, and industry officials provided data for a comparative analysis of gasoline, diesel, natural gas, methanol, and propane. (MLF)

  10. Alternative Fuels

    DTIC Science & Technology

    2009-06-11

    Swedish Biofuels AB • Cellulosic and algal feedstocks that are non-competitive with food material $ P r o d u c t P r o d u c t Traditional fuels...JP-8 BACK-UP SLIDES Unclassified 19 What Are Biofuels ? Cellulose “first generation”“second generation” C18:0 C16:1 Triglycerides (fats, oils

  11. Storage assembly for spent nuclear fuel

    SciTech Connect

    Lapides, M.E.

    1982-04-27

    A technique for storing spent fuel rods from a nuclear reactor is disclosed herein. This technique utilizes a housing including a closed inner chamber for containing the fuel rods and a thermally conductive member located partially within the housing chamber and partially outside the housing for transferring heat generated by the fuel rods from the chamber to the ambient surroundings. Particulate material is located within the chamber and surrounds the fuel rods contained therein. This material is selected to serve as a heat transfer media between the contained cells and the heat transferring member and, at the same time, stand ready to fuse into a solid mass around the contained cells if the heat transferring member malfunctions or otherwise fails to transfer the generated heat out of the housing chamber in a predetermined way.

  12. Thermal analysis of the failed equipment storage vault system

    SciTech Connect

    Jerrell, J.; Lee, S.Y.; Shadday, A.

    1995-07-01

    A storage facility for failed glass melters is required for radioactive operation of the Defense Waste Processing Facility (DWPF). It is currently proposed that the failed melters be stored in the Failed Equipment Storage Vaults (FESV`s) in S area. The FESV`s are underground reinforced concrete structures constructed in pairs, with adjacent vaults sharing a common wall. A failed melter is to be placed in a steel Melter Storage Box (MSB), sealed, and lowered into the vault. A concrete lid is then placed over the top of the FESV. Two melters will be placed within the FESV/MSB system, separated by the common wall. There is no forced ventilation within the vault so that the melter is passively cooled. Temperature profiles in the Failed Equipment Storage Vault Structures have been generated using the FLOW3D software to model heat conduction and convection within the FESV/MSB system. Due to complexities in modeling radiation with FLOW3D, P/THERMAL software has been used to model radiation using the conduction/convection temperature results from FLOW3D. The final conjugate model includes heat transfer by conduction, convection, and radiation to predict steady-state temperatures. Also, the FLOW3D software has been validated as required by the technical task request.

  13. Evaluation of MHTGR fuel reliability

    SciTech Connect

    Wichner, R.P.; Barthold, W.P.

    1992-07-01

    Modular High-Temperature Gas-Cooled Reactor (MHTGR) concepts that house the reactor vessel in a tight but unsealed reactor building place heightened importance on the reliability of the fuel particle coatings as fission product barriers. Though accident consequence analyses continue to show favorable results, the increased dependence on one type of barrier, in addition to a number of other factors, has caused the Nuclear Regulatory Commission (NRC) to consider conservative assumptions regarding fuel behavior. For this purpose, the concept termed ``weak fuel`` has been proposed on an interim basis. ``Weak fuel`` is a penalty imposed on consequence analyses whereby the fuel is assumed to respond less favorably to environmental conditions than predicted by behavioral models. The rationale for adopting this penalty, as well as conditions that would permit its reduction or elimination, are examined in this report. The evaluation includes an examination of possible fuel-manufacturing defects, quality-control procedures for defect detection, and the mechanisms by which fuel defects may lead to failure.

  14. Fuel cell

    SciTech Connect

    Struthers, R.C.

    1983-06-28

    An improved fuel cell comprising an anode section including an anode terminal, an anode fuel, and an anolyte electrolyte, a cathode section including a cathode terminal, an electron distributor and a catholyte electrolyte, an ion exchange section between the anode and cathode sections and including an ionolyte electrolyte, ion transfer membranes separating the ionolyte from the anolyte and the catholyte and an electric circuit connected with and between the terminals conducting free electrons from the anode section and delivering free electrons to the cathode section, said ionolyte receives ions of one polarity moving from the anolyte through the membrane related thereto preventing chemical equilibrium in the anode section and sustaining chemical reaction and the generating of free electrons therein, said ions received by the ionolyte from the anolyte release different ions from the ionolyte which move through the membrane between the ionolyte and catholyte and which add to the catholyte.

  15. Fuel additives

    SciTech Connect

    Gheysens, J.L.G.

    1990-11-27

    This patent describes a composition for the improvement of hydrocarbon fuels exhibiting a boiling range of gasoline being suitable for use in spark ignition-type engines. It comprises an aromatic amine; a polyaminated detergent; a catalyst comprising a colloidal suspension or amine salt of transition/alkali/alkaline earth metal organic coordinations having at least one metal oxidehydroxide linked to an alkyl chain via a carboxyl group; and a solvent comprising an alkanol-aliphatic ether oxygenated hydrocarbon.

  16. Future Fuels

    DTIC Science & Technology

    2006-04-01

    Storage Devices, Fuel Management, Gasification, Fischer-Tropsch, Syngas , Hubberts’s Peak UNCLAS UNCLAS UNCLAS UU 80 Dr. Sujata Millick (703) 696...traction power – mission payloads – mobile electric power • Improved survivability • Inherent modularity improves maintainability & upgradability ...threatened the output of the Ploesti oil fields and refineries. In the FT process, so-called syngas (a mixture of molecular hydrogen and carbon monoxide

  17. Fuel conditioner

    SciTech Connect

    Nelson, M.L.; Nelson, O.L. Jr.

    1988-06-28

    A fuel conditioner is described comprising 10 to 80% of a polar oxygenated hydrocarbon having an average molecular weight from about 250 to about 500, an acid acid number from about 25 to about 125, and a saponification number from about 30 to about 250; and 5 to 50% of an oxygenated compatibilizing agent having a solubility parameter of from about 8.8 to about 11.5 and moderate to strong hydrogen-bonding capacity.

  18. Alcohol fuels

    SciTech Connect

    Not Available

    1990-07-01

    Ethanol is an alcohol made from grain that can be blended with gasoline to extend petroleum supplies and to increase gasoline octane levels. Congressional proposals to encourage greater use of alternative fuels could increase the demand for ethanol. This report evaluates the growth potential of the ethanol industry to meet future demand increases and the impacts increased production would have on American agriculture and the federal budget. It is found that ethanol production could double or triple in the next eight years, and that American farmers could provide the corn for this production increase. While corn growers would benefit, other agricultural segments would not; soybean producers, for example could suffer for increased corn oil production (an ethanol byproduct) and cattle ranchers would be faced with higher feed costs because of higher corn prices. Poultry farmers might benefit from lower priced feed. Overall, net farm cash income should increase, and consumers would see slightly higher food prices. Federal budget impacts would include a reduction in federal farm program outlays by an annual average of between $930 million (for double current production of ethanol) to $1.421 billion (for triple production) during the eight-year growth period. However, due to an partial tax exemption for ethanol blended fuels, federal fuel tax revenues could decrease by between $442 million and $813 million.

  19. Fuel injection pump having voltage variation compensation

    SciTech Connect

    Takemoto, E.; Miyaki, M.; Norimatsu, H.; Hobo, N.; Tsuzuki, Y.; Konishi, Y.

    1986-08-05

    A fuel injection pump is described for internal combustion engine, comprising: an enclosure; pump means including a plunger rotatingly and reciprocally movable in the enclosure to define a compression chamber of variable volume, the pump means coupling the compression chamber to a fuel inlet during an intake stroke of the plunger and connecting the compression chamber to a fuel outlet during a compression stroke of the plunger to thereby initiate injection of fuel to the outlet, the pump means being responsive to the speed of rotation of the engine to pressurize the fuel in the inlet; means for detecting the speed of the engine; a source of voltage having a tendency to vary; solenoid valve means operable when a voltage is applied thereto from the source for providing a pressure relief action of the fuel in the compression chamber to terminate the injection of fuel; a memory storing trimming data in locations addressable as a function of the detected voltage and as a function of the detected engine speed; and control means for detecting the voltage of the source and responsive to the initiation of the fuel injection for determining the basic timing at which the fuel injection is to be terminated, reading trimming data out of the memory as a function of the detected voltage and as a function of the detected engine speed, correcting the basic timing in accordance with the trimming data and applying the voltage of the source to the solenoid valve means at the corrected timing to thereby terminate the fuel injection.

  20. Parameter Estimation of Spacecraft Fuel Slosh Model

    NASA Technical Reports Server (NTRS)

    Gangadharan, Sathya; Sudermann, James; Marlowe, Andrea; Njengam Charles

    2004-01-01

    Fuel slosh in the upper stages of a spinning spacecraft during launch has been a long standing concern for the success of a space mission. Energy loss through the movement of the liquid fuel in the fuel tank affects the gyroscopic stability of the spacecraft and leads to nutation (wobble) which can cause devastating control issues. The rate at which nutation develops (defined by Nutation Time Constant (NTC can be tedious to calculate and largely inaccurate if done during the early stages of spacecraft design. Pure analytical means of predicting the influence of onboard liquids have generally failed. A strong need exists to identify and model the conditions of resonance between nutation motion and liquid modes and to understand the general characteristics of the liquid motion that causes the problem in spinning spacecraft. A 3-D computerized model of the fuel slosh that accounts for any resonant modes found in the experimental testing will allow for increased accuracy in the overall modeling process. Development of a more accurate model of the fuel slosh currently lies in a more generalized 3-D computerized model incorporating masses, springs and dampers. Parameters describing the model include the inertia tensor of the fuel, spring constants, and damper coefficients. Refinement and understanding the effects of these parameters allow for a more accurate simulation of fuel slosh. The current research will focus on developing models of different complexity and estimating the model parameters that will ultimately provide a more realistic prediction of Nutation Time Constant obtained through simulation.

  1. Plasma Brightenings in a Failed Solar Filament Eruption

    NASA Astrophysics Data System (ADS)

    Li, Y.; Ding, M. D.

    2017-03-01

    Failed filament eruptions are solar eruptions that are not associated with coronal mass ejections. In a failed filament eruption, the filament materials usually show some ascending and falling motions as well as generating bright EUV emissions. Here we report a failed filament eruption (SOL2016-07-22) that occurred in a quiet-Sun region observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. In this event, the filament spreads out but gets confined by the surrounding magnetic field. When interacting with the ambient magnetic field, the filament material brightens up and flows along the magnetic field lines through the corona to the chromosphere. We find that some materials slide down along the lifting magnetic structure containing the filament and impact the chromosphere, and through kinetic energy dissipation, cause two ribbon-like brightenings in a wide temperature range. There is evidence suggesting that magnetic reconnection occurs between the filament magnetic structure and the surrounding magnetic fields where filament plasma is heated to coronal temperatures. In addition, thread-like brightenings show up on top of the erupting magnetic fields at low temperatures, which might be produced by an energy imbalance from a fast drop of radiative cooling due to plasma rarefaction. Thus, this single event of a failed filament eruption shows the existence of a variety of plasma brightenings that may be caused by completely different heating mechanisms.

  2. Understanding and Working with "Failed Communication" in Telecollaborative Exchanges

    ERIC Educational Resources Information Center

    O'Dowd, Robert; Ritter, Markus

    2006-01-01

    It is by now well established that telecollaborative exchanges frequently end in "failed communication" and do not automatically bring about successful negotiation of meaning between the learners. Instead, the intended pedagogic and linguistic aims of online interaction are repeatedly missed, and projects may end in low levels of participation,…

  3. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  4. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  5. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  6. "It's All Human Error!": When a School Science Experiment Fails

    ERIC Educational Resources Information Center

    Viechnicki, Gail Brendel; Kuipers, Joel

    2006-01-01

    This paper traces the sophisticated negotiations to re-inscribe the authority of Nature when a school science experiment fails during the enactment of a highly rated science curriculum unit. Drawing on transcriptions from classroom videotapes, we identify and describe four primary patterns of interaction that characterize this process, arguing…

  7. Ballooning osteolysis in 71 failed total ankle arthroplasties

    PubMed Central

    Singh, Gurpal; Reichard, Theresa; Hameister, Rita; Awiszus, Friedemann; Schenk, Katja; Feuerstein, Bernd; Roessner, Albert; Lohmann, Christoph

    2016-01-01

    Background and purpose Aseptic loosening is a major cause of failure in total ankle arthroplasty (TAA). In contrast to other total joint replacements, large periarticular cysts (ballooning osteolysis) have frequently been observed in this context. We investigated periprosthetic tissue responses in failed TAA, and performed an element analysis of retrieved tissues in failed TAA. Patients and methods The study cohort consisted of 71 patients undergoing revision surgery for failed TAA, all with hydroxyapatite-coated implants. In addition, 5 patients undergoing primary TAA served as a control group. Radiologically, patients were classified into those with ballooning osteolysis and those without, according to defined criteria. Histomorphometric, immunohistochemical, and elemental analysis of tissues was performed. Von Kossa staining and digital microscopy was performed on all tissue samples. Results Patients without ballooning osteolysis showed a generally higher expression of lymphocytes, and CD3+, CD11c+, CD20+, and CD68+ cells in a perivascular distribution, compared to diffuse expression. The odds of having ballooning osteolysis was 300 times higher in patients with calcium content >0.5 mg/g in periprosthetic tissue than in patients with calcium content ≤0.5 mg/g (p < 0.001). Interpretation There have been very few studies investigating the pathomechanisms of failed TAA and the cause-effect nature of ballooning osteolysis in this context. Our data suggest that the hydroxyapatite coating of the implant may be a contributory factor. PMID:27196532

  8. Why Young People Fail To Get and Hold Jobs.

    ERIC Educational Resources Information Center

    New York State Dept. of Labor, Albany.

    This booklet provides advice to young people seeking their first jobs on how to avoid the pitfalls that have caused others to lose jobs or fail to be hired. Topics discussed in short, one-page sections include appearance, attitude and behavior, ignorance of labor market facts, misrepresentation, sensitivity about a physical defect, unrealistic…

  9. 9 CFR 442.5 - Handling of failed product.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Handling of failed product. 442.5 Section 442.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... upon testing in accordance with the methods prescribed in § 442.2 of this subchapter shall be...

  10. 9 CFR 442.5 - Handling of failed product.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Handling of failed product. 442.5 Section 442.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... upon testing in accordance with the methods prescribed in § 442.2 of this subchapter shall be...

  11. Management of adults with prior failed hypospadias surgery

    PubMed Central

    Craig, James R.; Wallis, Chad; Brant, William O.; Hotaling, James M.

    2014-01-01

    Hypospadias is one of the most prevalent anomalies of the male genitalia. Contemporary hypospadias repair is very successful, but patients that have the surgery fail often require multiple surgeries throughout their life. Complications from failed hypospadias repairs have a significant impact on patients both psychologically and physically. Failed hypospadias repair encompasses a spectrum of problems that include hypospadias recurrence with an ectopic meatus, urethral fistula, urethral stricture, and ventral penile curvature. Repairs of hypospadias complications can be challenging due to the poor quality of surrounding tissue from disruption of normal vasculature in the re-operative field associated with the underlying disorder. One of the most challenging issues is dealing with urethral strictures. There have been multiple methods described at repairs of these in both a single stage and multiple staged procedures. Particular attention has been directed towards applications of grafts due to worse outcomes with flaps. Buccal mucosa has emerged as the leading graft material in staged repairs. When counseling patients with failed hypospadias it is important to discuss the expected outcome as repairs directed towards a terminally positioned meatus with a straight phallus may require multiple surgeries due to post-operative complications as well as the necessity of proceeding in a staged approach. PMID:26816767

  12. When Consensus Decision-Making Fails: A Case Study.

    ERIC Educational Resources Information Center

    Savage, Grant T.

    Habermas's theory of dialogue was used to evaluate the process of decision making that occurred in a labor-management committee's meeting to discuss flextime. The study attempted to determine why, at that meeting, the committee's consensus process of decision making failed. W.R. Bion's theory of unconscious group motives was also used to…

  13. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Failed lots/rework procedure. 983.152 Section 983.152 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  14. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Failed lots/rework procedure. 983.52 Section 983.52 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  15. Solutions for Failing High Schools: Converging Visions and Promising Models.

    ERIC Educational Resources Information Center

    Legters, Nettie; Balfanz, Robert; McPartland, James

    Promising solutions to the failings of traditional comprehensive high schools were reviewed to identify basic principles and strategies for improving high schools nationwide. Selected research studies, policy documents, and promising high school programs were reviewed. The review revealed the following principles for helping high schools better…

  16. Failing Boys! Beyond Crisis, Moral Panic and Limiting Stereotypes

    ERIC Educational Resources Information Center

    Martino, Wayne

    2011-01-01

    For some time now, school boards, Ministries of Education, and the popular media have been expressing concerns about failing boys and how best to meet their needs, framing these concerns in terms of a crisis in which boys are the "new disadvantaged". This perspective does not provide an accurate representation of the problem and, in fact, detracts…

  17. Improving Charter School Accountability: The Challenge of Closing Failing Schools

    ERIC Educational Resources Information Center

    Osborne, David

    2012-01-01

    Today some 5,600 charter schools are in operation, with more than two million students. Some critics persist in a fruitless argument that these schools have failed, despite a mountain of evidence to the contrary. But regardless of your opinion about them, charter schools are here to stay. Those concerned about public education should quit debating…

  18. Depressed phosphatidic acid-induced contractile activity of failing cardiomyocytes.

    PubMed

    Tappia, Paramjit S; Maddaford, Thane G; Hurtado, Cecilia; Panagia, Vincenzo; Pierce, Grant N

    2003-01-10

    The effects of phosphatidic acid (PA), a known inotropic agent, on Ca(2+) transients and contractile activity of cardiomyocytes in congestive heart failure (CHF) due to myocardial infarction were examined. In control cells, PA induced a significant increase (25%) in active cell shortening and Ca(2+) transients. The phospholipase C (PLC) inhibitor, 2-nitro-4-carboxyphenyl N,N-diphenylcarbonate, blocked the positive inotropic action induced by PA, indicating that PA induces an increase in contractile activity and Ca(2+) transients through stimulation of PLC. Conversely, in failing cardiomyocytes there was a loss of PA-induced increase in active cell shortening and Ca(2+) transients. PA did not alter resting cell length. Both diastolic and systolic [Ca(2+)] were significantly elevated in the failing cardiomyocytes. In vitro assessment of the cardiac sarcolemmal (SL) PLC activity revealed that the impaired failing cardiomyocyte response to PA was associated with a diminished stimulation of SL PLC activity by PA. Our results identify an important defect in the PA-PLC signaling pathway in failing cardiomyocytes, which may have significant implications for the depressed contractile function during CHF.

  19. 78 FR 4349 - Records of Failed Insured Depository Institutions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... of the institution but also materials that have no relevance to its business, or which lack evidentiary value and would not ordinarily be considered ``records.'' In addition, advances in information... obtains from a failed insured depository institution, regardless of its significance or evidentiary...

  20. Majority-voted logic fail-sense circuit

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1977-01-01

    Fail-sense circuit has majority-voted logic component which receives three error voltage signals that are sensed at single point by three error amplifiers. If transistor shorts, only one signal is required to operate; if transistor opens, two signals are required.

  1. Why the Merit Pay System Failed in the Federal Government.

    ERIC Educational Resources Information Center

    Silverman, Buddy Robert S.

    1983-01-01

    Discusses the implementation of the merit pay system in the federal government and the ten unsurmountable problems that caused it to fail; i.e., unintended statutory provisions, open-ended regulations, novice technical assistance, drifting implementation policies, administrative errors, complicated systems, inconsistent employee treatment,…

  2. Preventing Suicide: A Mission Too Big to Fail

    DTIC Science & Technology

    2013-03-01

    Soldier Fitness Program Evaluation, Report #3,” 23. 129 Ibid. 130 Kerry L . Knox and Robert M . Bossarte, “Suicide Prevention for Veterans and Active Duty...Preventing Suicide: A Mission Too Big to Fail by Ms. Gloria Duck Lieutenant Colonel Timothy Holman Ms. Jennifer Jessup ...Lieutenant Colonel Timothy Holman United States Army Ms. Jennifer Jessup Department of Veterans Affairs Civilian Colonel Keith

  3. 9 CFR 442.5 - Handling of failed product.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Handling of failed product. 442.5 Section 442.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... upon testing in accordance with the methods prescribed in § 442.2 of this subchapter shall be...

  4. Super-Earths as Failed Cores in Orbital Migration Traps

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yasuhiro

    2016-11-01

    I explore whether close-in super-Earths were formed as rocky bodies that failed to grow fast enough to become the cores of gas giants before the natal protostellar disk dispersed. I model the failed cores’ inward orbital migration in the low-mass or type I regime to stopping points at distances where the tidal interaction with the protostellar disk applies zero net torque. The three kinds of migration traps considered are those due to the dead zone's outer edge, the ice line, and the transition from accretion to starlight as the disk's main heat source. As the disk disperses, the traps move toward final positions near or just outside 1 au. Planets at this location exceeding about 3 M ⊕ open a gap, decouple from their host traps, and migrate inward in the high-mass or type II regime to reach the vicinity of the star. I synthesize the population of planets that formed in this scenario, finding that a fraction of the observed super-Earths could have been failed cores. Most super-Earths that formed this way have more than 4 M ⊕, so their orbits when the disks dispersed were governed by type II migration. These planets have solid cores surrounded by gaseous envelopes. Their subsequent photoevaporative mass loss is most effective for masses originally below about 6 M ⊕. The failed core scenario suggests a division of the observed super-Earth mass-radius diagram into five zones according to the inferred formation history.

  5. What is the optimal rate of failed extubation?

    PubMed Central

    2012-01-01

    Failed extubation (FE), defined as reintubation 48 or 72 hours after planned extubation, occurs in a significant percentage of patients and is associated with a substantial burden of morbidity and mortality. This commentary reviews the literature describing FE rates and the clinical consequences of FE and proposes an 'optimal' rate of FE as well as avenues for future research. PMID:22356725

  6. Test and analysis of a stitched RFI graphite-epoxy panel with a fuel access door

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.; Waters, W. Allen, Jr.

    1994-01-01

    A stitched RFI graphite-epoxy panel with a fuel access door was analyzed using a finite element analysis and loaded to failure in compression. The panel was initially 56-inches long and 36.75-inches wide and the oval access door was 18-inches long and 15-inches wide. The panel was impact damaged with impact energy of 100 ft-lb prior to compressive loading; however, no impact damage was detectable visually or by A-scan. The panel carried a failure load of 695,000 Ib and global failure strain of .00494 in/in. Analysis indicated the panel would fail due to collapse at a load of 688,100 Ib. The test data indicate that the maximum strain in a region near the access door was .0096 in/in and analysis indicates a local surface strain of .010 in/in at the panel's failure load. The panel did not fail through the impact damage, but instead failed through bolt holes for attachment of the access door in a region of high strain.

  7. The relationship between fuel lubricity and diesel injection system wear

    NASA Astrophysics Data System (ADS)

    Lacy, Paul I.

    1992-01-01

    Use of low-lubricity fuel may have contributed to increased failure rates associated with critical fuel injection equipment during the 1991 Operation Desert Storm. However, accurate quantitative analysis of failed components from the field is almost impossible due to the unique service history of each pump. This report details the results of pump stand tests with fuels of equal viscosity, but widely different lubricity. Baseline tests were also performed using reference no. 2 diesel fuel. Use of poor lubricity fuel under these controlled conditions was found to greatly reduce both pump durability and engine performance. However, both improved metallurgy and fuel lubricity additives significantly reduced wear. Good correlation was obtained between standard bench tests and lightly loaded pump components. However, high contact loads on isolated components produced a more severe wear mechanism that is not well reflected by the Ball-on-Cylinder Lubricity Evaluator.

  8. REACTOR FUEL ELEMENTS TESTING CONTAINER

    DOEpatents

    Whitham, G.K.; Smith, R.R.

    1963-01-15

    This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

  9. Fuel Burn Estimation Model

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano

    2011-01-01

    Conclusions: Validated the fuel estimation procedure using flight test data. A good fuel model can be created if weight and fuel data are available. Error in assumed takeoff weight results in similar amount of error in the fuel estimate. Fuel estimation error bounds can be determined.

  10. Aviation fuels outlook

    NASA Technical Reports Server (NTRS)

    Momenthy, A. M.

    1980-01-01

    Options for satisfying the future demand for commercial jet fuels are analyzed. It is concluded that the most effective means to this end are to attract more refiners to the jet fuel market and encourage development of processes to convert oil shale and coal to transportation fuels. Furthermore, changing the U.S. refineries fuel specification would not significantly alter jet fuel availability.

  11. A Review of NDE Methods for Detecting and Monitoring of Atmospheric SCC in Dry Cask Storage Canisters for Used Nuclear Fuel

    SciTech Connect

    Meyer, Ryan M.; Hanson, Brady D.; Sorenson, Ken B.

    2013-04-01

    Dry cask storage systems (DCSSs) for used nuclear fuel (UNF) were originally envisioned for storage periods of short duration (~ a few decades). However, uncertainty challenges the opening of a permanent repository for UNF implying that UNF will need to remain in dry storage for much longer durations than originally envisioned (possibly for centuries). Thus, aging degradation of DCSSs becomes an issue that may not have been sufficiently considered in the design phase and that can challenge the efficacy of very long-term storage of UNF. A particular aging degradation concern is atmospheric stress corrosion cracking (SCC) of DCSSs located in marine environments. In this report, several nondestructive (NDE) methods are evaluated with respect to their potential for effective monitoring of atmospheric SCC in welded canisters of DCSSs. Several of the methods are selected for evaluation based on their usage for in-service inspection applications in the nuclear power industry. The technologies considered include bulk ultrasonic techniques, acoustic emission, visual techniques, eddy current, and guided ultrasonic waves.

  12. Review of NDE Methods for Detection and Monitoring of Atmospheric SCC in Welded Canisters for the Storage of Used Nuclear Fuel

    SciTech Connect

    Meyer, Ryan M.; Pardini, Allan F.; Hanson, Brady D.; Sorenson, Ken B.

    2013-01-14

    Dry cask storage systems (DCSSs) for used nuclear fuel (UNF) were originally envisioned for storage periods of short duration (~ a few decades). However, uncertainty challenges the opening of a permanent repository for UNF implying that UNF will need to remain in dry storage for much longer durations than originally envisioned (possibly for centuries). Thus, aging degradation of DCSSs becomes an issue that may not have been sufficiently considered in the design phase and that can challenge the efficacy of very long-term storage of UNF. A particular aging degradation concern is atmospheric stress corrosion cracking (SCC) of DCSSs located in marine environments. In this report, several nondestructive (NDE) methods are evaluated with respect to their potential for effective monitoring of atmospheric SCC in welded canisters of DCSSs. Several of the methods are selected for evaluation based on their usage for in-service inspection applications in the nuclear power industry. The technologies considered include bulk ultrasonic techniques, acoustic emission, visual techniques, eddy current, and guided ultrasonic waves.

  13. 146. FUEL LINE TO SKID 2 (FUEL LOADER) IN FUEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    146. FUEL LINE TO SKID 2 (FUEL LOADER) IN FUEL CONTROL ROOM (215), LSB (BLDG. 751). LIQUID NITROGEN/HELIUM HEAT EXCHANGER ON RIGHT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  14. Fuel extender

    SciTech Connect

    Dorn, G.K.; Gilbert, H.A.

    1989-02-21

    An efficient and cost competitive fuel extender liquid is described for blending with lead-free gasoline as an additive thereto in a maximum amount of up to about 35% thereof with 65% by volume of the gasoline in a blended mixture wherein. The content of the extender in the resultant fuel as proportioned on the basis of its thus representative maximum content consists essentially of: naphtha X as represented by C/sub 4/, C/sub 5/ and C/sub 6/ hydrocarbons having a Reid vapor pressure of about 8.5 to 9.6 per ASTM, D323 test procedure and an initial distillation point of about 101/sup 0/F. and an end point of about 280/sup 0/F. within a range of about 10 to 25% by volume, about 3.8 to 6.0% by volume of anhydrous ethanol, a stabilizing amount of a water repellent of the class consisting of ethyl acetate and methyl isotubyl ketone; and about 4 to 10.5% by volume of aromatics benzene and toluene, of benzene and xylene or of benzene with toluene and xylene; the extender having a specific gravity substantially comparable with that of the lead-free gasoline to which it is to be added and having phase stability in the presence of water when mixed with the gasoline.

  15. Microbial water quality before and after the repair of a failing onsite wastewater treatment system adjacent to coastal waters

    USGS Publications Warehouse

    Conn, K.E.; Habteselassie, M.Y.; Denene, Blackwood A.; Noble, R.T.

    2012-01-01

    Aims: The objective was to assess the impacts of repairing a failing onsite wastewater treatment system (OWTS, i.e., septic system) as related to coastal microbial water quality. Methods and Results: Wastewater, groundwater and surface water were monitored for environmental parameters, faecal indicator bacteria (total coliforms, Escherichia coli, enterococci) and the viral tracer MS2 before and after repairing a failing OWTS. MS2 results using plaque enumeration and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) often agreed, but inhibition limited the qRT-PCR assay sensitivity. Prerepair, MS2 persisted in groundwater and was detected in the nearby creek; postrepair, it was not detected. In groundwater, total coliform concentrations were lower and E.??coli was not detected, while enterococci concentrations were similar to prerepair levels. E.??coli and enterococci surface water concentrations were elevated both before and after the repair. Conclusions: Repairing the failing OWTS improved groundwater microbial water quality, although persistence of bacteria in surface water suggests that the OWTS was not the singular faecal contributor to adjacent coastal waters. A suite of tracers is needed to fully assess OWTS performance in treating microbial contaminants and related impacts on receiving waters. Molecular methods like qRT-PCR have potential but require optimization. Significance and Impact of Study: This is the first before and after study of a failing OWTS and provides guidance on selection of microbial tracers and methods. ?? 2011 The Authors. Journal of Applied Microbiology ?? 2011 The Society for Applied Microbiology.

  16. Characterization plan for Fort St. Vrain and Peach Bottom graphite fuels

    SciTech Connect

    Maarschman, S.C.; Berting, F.M.; Clemmer, R.G.; Gilbert, E.R.; Guenther, R.J.; Morgan, W.C.; Sliva, P.

    1993-09-01

    Part of Fort St. Vrain (FSV) and most of the Peach Bottom (PB) reactor spent fuels are currently stored at INEL and may remain in storage for many years before disposal. Three disposal pathways have been proposed: intact disposal, fuels partially disassembled and the high-level waste fraction conditioned prior to disposal, and fuels completed disassembled and conditioned prior to disposal. Many options exist within each of these pathways. PNL evaluated the literature and other reference to develop a fuels characterization plan for these fuels. This plan provides guidance for the characteristics of the fuel which will be needed to pursue any of the storage or disposal pathways. It also provides a suggested fuels monitoring program for the current storage facilities. This report recommends a minimum of 7 fuel elements be characterized: PB Core 1 fuel: one Type II nonfailed element, one Type II failed element, and one Type III nonfailed element; PB Core 2 fuel: two Type II nonfailed fuel elements; and FSV fuel: at least two fuel blocks from regions of high temperature and fluence and long in-reactor performance (preferably at reactor end-of- life). Selection of PB fuel elements should focus on these between radial core position 8 and 14 and on compacts between compact numbers 10 and 20. Selection of FSV fuel elements should focus on these from Fuel Zones II and III, located in Core Layers 6, 7, and possibly 8.

  17. Possibility of using a lithotrophic iron-oxidizing microbial fuel cell as a biosensor for detecting iron and manganese in water samples.

    PubMed

    Tran, Phuong Hoang Nguyen; Luong, Tha Thanh Thi; Nguyen, Thuy Thu Thi; Nguyen, Huy Quang; Duong, Hop Van; Kim, Byung Hong; Pham, Hai The

    2015-10-01

    Iron-oxidizing bacterial consortia can be enriched in microbial fuel cells (MFCs) operated with ferrous iron as the sole electron donor. In this study, we investigated the possibility of using such lithotrophic iron-oxidizing MFC (LIO-MFC) systems as biosensors to monitor iron and manganese in water samples. When operated with anolytes containing only ferrous iron as the sole electron donor, the experimented LIO-MFCs generated electrical currents in response to the presence of Fe(2+) in the anolytes. For the concentrations of Fe(2+) in the range of 3-20 mM, a linear correlation between the current and the concentration of Fe(2+) could be achieved (r(2) = 0.98). The LIO-MFCs also responded to the presence of Mn(2+) in the anolytes but only when the Mn(2+) concentration was less than 3 mM. The presence of other metal ions such as Ni(2+) or Pb(2+) in the anolytes reduced the Fe(2+)-associated electricity generation of the LIO-MFCs at various levels. Organic compounds, when present at a non-excessive level together with Fe(2+) in the anolytes, did not affect the generation of electricity, although the compounds might serve as alternative electron donors for the anode bacteria. The performance of the LIO-MFCs was also affected to different degrees by operational parameters, including surrounding temperature, pH of the sample, buffer strength and external resistance. The results proved the potential of LIO-MFCs as biosensors sensing Fe(2+) in water samples with a significant specificity. However, the operation of the system should be in compliance with an optimal procedure to ensure reliable performance.

  18. Fuel cells: A survey

    NASA Technical Reports Server (NTRS)

    Crowe, B. J.

    1973-01-01

    A survey of fuel cell technology and applications is presented. The operating principles, performance capabilities, and limitations of fuel cells are discussed. Diagrams of fuel cell construction and operating characteristics are provided. Photographs of typical installations are included.

  19. Renewable Fuel Standard Program

    EPA Pesticide Factsheets

    Information about regulations, developed by EPA, in collaboration with refiners, renewable fuel producers, and many other stakeholders, that ensure that transportation fuel sold in the United States contains a minimum volume of renewable fuel.

  20. Fail-safe designs for large capacity battery systems

    DOEpatents

    Kim, Gi-Heon; Smith, Kandler; Ireland, John; Pesaran, Ahmad A.; Neubauer, Jeremy

    2016-05-17

    Fail-safe systems and design methodologies for large capacity battery systems are disclosed. The disclosed systems and methodologies serve to locate a faulty cell in a large capacity battery, such as a cell having an internal short circuit, determine whether the fault is evolving, and electrically isolate the faulty cell from the rest of the battery, preventing further electrical energy from feeding into the fault.

  1. Results of Trabectome Surgery Following Failed Glaucoma Tube Shunt Implantation

    PubMed Central

    Mosaed, Sameh; Chak, Garrick; Haider, Asghar; Lin, Ken Y.; Minckler, Don S.

    2015-01-01

    Abstract To evaluate the safety and efficacy of Trabectome after failed tube shunt surgery. Twenty patients with prior failed tube shunt surgery who underwent Trabectome alone were included. All patients had at least 3 months of follow-up. Outcomes measured included intraocular pressure (IOP), glaucoma medications, and secondary glaucoma surgeries. The success for Kaplan–Meier survival analysis is defined as IOP ≤21 mm Hg, IOP reduced by at least 20% from preoperative IOP, and no secondary glaucoma surgery. Mean preoperative IOP was 23.7 ± 6.4 mm Hg and mean number of glaucoma medications was 3.2 ± 1.5. At 12 months, IOP was reduced to 15.5 ± 3.2 mm Hg (P = 0.05) and number of medications was reduced to 2.4 ± 1.5 (P = 0.44). Survival rate at 12 months was 84% and 3 patients required additional glaucoma surgery with 15 patients reaching 12 months follow-up. Other than failure of IOP control and transient hypotony (IOP < 3 mm Hg) day 1 in 2 cases, there were no adverse events. Trabecular bypass procedures have traditionally been considered an approach appropriate for early-to-moderate glaucoma; however, our study indicates benefit in refractory glaucoma as well. Eyes that are prone to conjunctival scarring and hypertrophic wound healing, such as those who have failed tube shunt surgery, may benefit from procedures that avoid conjunctival incision such as Trabectome. This study indicates potential benefits in this patient population. Trabectome was safe and effective in reducing IOP at 1-year follow-up in patients with prior failed tube shunt surgery, but not effective in reducing medication reliance in these patients. PMID:26222842

  2. Paying for innovation. Failed strategies add to hospitals' reimbursement losses.

    PubMed

    Pallarito, K

    Hospitals across the country are struggling to balance revenue shortfalls and cost increases as the lid on government and private-payer payments closes tighter. They're also grappling with losses on failed physician and HMO investments, the expense of new medical technologies and larger-than-planned costs related to "millennium bug" cures. This is the second part of a two-part series on financial turmoil in healthcare.

  3. Reorganized PKA-AKAP associations in the failing human heart.

    PubMed

    Aye, Thin-Thin; Soni, Siddarth; van Veen, Toon A B; van der Heyden, Marcel A G; Cappadona, Salvatore; Varro, Andras; de Weger, Roel A; de Jonge, Nicolaas; Vos, Marc A; Heck, Albert J R; Scholten, Arjen

    2012-02-01

    Here we reveal that the characterization of large-scale re-arrangements of signaling scaffolds induced by heart failure can serve as a novel concept to identify more specific therapeutic targets. In the mammalian heart, the cAMP pathway, with the cAMP-dependent protein kinase (PKA) in a central role, acts directly downstream of adrenergic receptors to mediate cardiac contractility and rhythm. Heart failure, characterized by severe alterations in adrenergic stimulation is, amongst other interventions, often treated with β-blockers. Contrasting results, however, have shown both beneficial and detrimental effects of decreased cAMP levels in failing hearts. We hypothesize that the origin of this behavior lies in the complex spatiotemporal organization of the regulatory subunit of PKA (PKA-R), which associates tightly with various A-kinase anchoring proteins (AKAPs) to specifically localize PKA's activity. Using chemical proteomics directly applied to human patient and control heart tissue we demonstrate that the association profile of PKA-R with several AKAPs is severely altered in the failing heart, for instance effecting the interaction between PKA and the novel AKAP SPHKAP was 6-fold upregulated upon failing heart conditions. Also a significant increase in captured cGMP-dependent protein kinase (PKG) and phosphodiesterase 2 (PDE2) was observed. The observed altered profiles can already explain many aspects of the aberrant cAMP-response in the failing human heart, validating that this dataset may provide a resource for several novel, more specific, treatment options. This article is part of a Special Issue entitled "Local Signaling in Myocytes".

  4. Failing underperforming students: the role of grading in practice assessment.

    PubMed

    Heaslip, Vanessa; Scammell, Janet M E

    2012-03-01

    Nursing is essentially a practice discipline, informed by a theoretical base. It is crucial that students have a rigorous preparation in both theoretical and practical elements during their pre-registration programme. The aim of educationalists is to produce students fit for purpose and practice, but concerns have been raised internationally regarding students competence at the point of registration. There is evidence that some practice based assessors experience difficulties in failing incompetent students. Assessment of practice is often judged on a pass/fail rather than a graded basis in a number of health professional programmes. It could be argued that pass or fail provides limited feedback to students concerning exactly how well or poorly they have performed. This paper will explore these issues through focusing on selected findings from a service evaluation of a practice assessment tool incorporating grading of practice of pre-registration nursing students from one university in the United Kingdom (UK). Using convenience sampling, a questionnaire survey was completed by 107 adult, mental health and child health nursing students (51% response) and 112 mentors (practice-based assessors) (86% response) from all nursing fields. Amongst other issues, the evaluation identified that whilst mentors valued the opportunity to grade practice and perceived that the tool enabled them to be more discerning in the allocation of pass grades, some lacked confidence in failing students. The findings are discussed in the context of the wider debate around clinical competence in new nurse registrants and it is concluded that whilst assessing 'borderline' students will always be a testing experience, grading systems may help the assessor to be more discriminatory.

  5. Rescue of failed filtering blebs with ab interno trephination.

    PubMed

    Shihadeh, Wisam A; Ritch, Robert; Liebmann, Jeffrey M

    2006-06-01

    We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) <21 mm Hg and at least a 20% reduction from baseline on the same or fewer number of pretrephination medications, 30/40 eyes (75%) fit these criteria over the entire course of follow-up. Among all 40 eyes, there was a significant reduction of IOP from pretrephination to 3 months (P<.001). The percentage of patients requiring 2 or more medications declined from 90% pretrephination to 21% at 3 months (P<.0001), and was stable thereafter. Some patients were able to eliminate all medications. Patients who did not meet the criteria of success regained successful IOP control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.

  6. Future aviation fuels overview

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    The outlook for aviation fuels through the turn of the century is briefly discussed and the general objectives of the NASA Lewis Alternative Aviation Fuels Research Project are outlined. The NASA program involves the evaluation of potential characteristics of future jet aircraft fuels, the determination of the effects of those fuels on engine and fuel system components, and the development of a component technology to use those fuels.

  7. Fuel injection apparatus for internal combustion engines

    SciTech Connect

    Yamaguchi, S.; Ishiwata, H.

    1988-03-15

    A fuel injection apparatus for internal combustion engines is described comprising: a fuel injection pump which has a plunger caused to carry out a least reciprocal movement in a predetermined pattern in a bore formed in a plunger barrel to pressurize fuel in the plunge barrel and at least one control sleeve fitted on the plunger, a first actuator for regulating the position of the control sleeve to regulate the fuel injection rate; a second actuator for regulating the position of the plunger to regulate the fuel injection quantity; a first means responsive to at least one condition signal indicating the operating condition of the internal combustion engine for drivingly controlling the first and second actuators in such a way that the optimum fuel injection rate and fuel injection quantity can be obtained at each instant; a detecting means for detecting any trouble occurring in the control system for regulating the position of the control sleeve; and a second means for limiting the control operation by the first means so that an excessive rise in the inner pressure of the cylinders in the internal combustion engine is prevented when the occurrence of trouble is detected by the detecting means.

  8. Teach Your Students to Fail Better with Design Thinking

    ERIC Educational Resources Information Center

    Long, Christian

    2012-01-01

    Design thinking is about using design to improve the human experience. It combines collaboration, systems thinking, and a balance of creative and analytical habits. It also fuels what the students want for themselves: making an impact on the real world in real time and having adults take their passions seriously. The process essentially comes down…

  9. Effect of hydrocarbon fuel type on fuel

    NASA Technical Reports Server (NTRS)

    Wong, E. L.; Bittker, D. A.

    1982-01-01

    A modified jet fuel thermal oxidation tester (JFTOT) procedure was used to evaluate deposit and sediment formation for four pure hydrocarbon fuels over the temperature range 150 to 450 C in 316-stainless-steel heater tubes. Fuel types were a normal alkane, an alkene, a naphthene, and an aromatic. Each fuel exhibited certain distinctive deposit and sediment formation characteristics. The effect of aluminum and 316-stainless-steel heater tube surfaces on deposit formation for the fuel n-decane over the same temperature range was investigated. Results showed that an aluminum surface had lower deposit formation rates at all temperatures investigated. By using a modified JFTOT procedure the thermal stability of four pure hydrocarbon fuels and two practical fuels (Jet A and home heating oil no. 2) was rated on the basis of their breakpoint temperatures. Results indicate that this method could be used to rate thermal stability for a series of fuels.

  10. Fuel cell technology: A sweeter fuel

    NASA Astrophysics Data System (ADS)

    Kendall, Kevin

    2002-12-01

    Eating sugar gives us a boost when we feel tired because our cells use it as fuel to produce energy. Likewise, sugar can now be used to produce power in artificial biological fuel cells that function in a physiological environment.

  11. Fuel processor for fuel cell power system

    DOEpatents

    Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

    1987-01-01

    A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

  12. Fuel Reformer Nozzle Development

    NASA Technical Reports Server (NTRS)

    Lai, Ming-Chia D.

    2003-01-01

    The fellowship work this summer will be in support of the development of a fuel mixer for a liquid fuel reformer that is upstream of a fuel cell. Tasks for the summer shall consist of design of a fuel mixer, setup of the laser diagnostics for determining the degree of fuel mixing, and testing of the fuel mixer. The fuel mixer shall be a venturi section with fuel injected at or near the throat, and an air swirler upstream of the venturi. Data to determine the performance of the mixer shall be taken using a Phase Doppler Particle Analyzer (PDPA).

  13. Internal reforming fuel cell assembly with simplified fuel feed

    DOEpatents

    Farooque, Mohammad; Novacco, Lawrence J.; Allen, Jeffrey P.

    2001-01-01

    A fuel cell assembly in which fuel cells adapted to internally reform fuel and fuel reformers for reforming fuel are arranged in a fuel cell stack. The fuel inlet ports of the fuel cells and the fuel inlet ports and reformed fuel outlet ports of the fuel reformers are arranged on one face of the fuel cell stack. A manifold sealing encloses this face of the stack and a reformer fuel delivery system is arranged entirely within the region between the manifold and the one face of the stack. The fuel reformer has a foil wrapping and a cover member forming with the foil wrapping an enclosed structure.

  14. A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

    NASA Technical Reports Server (NTRS)

    Otugen, M. Volkan

    1997-01-01

    Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of

  15. NUCLEAR REACTOR FUEL-BREEDER FUEL ELEMENT

    DOEpatents

    Currier, E.L. Jr.; Nicklas, J.H.

    1962-08-14

    A fuel-breeder fuel element was developed for a nuclear reactor wherein discrete particles of fissionable material are dispersed in a matrix of fertile breeder material. The fuel element combines the advantages of a dispersion type and a breeder-type. (AEC)

  16. Fuel performance models for high-temperature gas-cooled reactor core design

    SciTech Connect

    Stansfield, O.M.; Simon, W.A.; Baxter, A.M.

    1983-09-01

    Mechanistic fuel performance models are used in high-temperature gas-cooled reactor core design and licensing to predict failure and fission product release. Fuel particles manufactured with defective or missing SiC, IPyC, or fuel dispersion in the buffer fail at a level of less than 5 x 10/sup -4/ fraction. These failed particles primarily release metallic fission products because the OPyC remains intact on 90% of the particles and retains gaseous isotopes. The predicted failure of particles using performance models appears to be conservative relative to operating reactor experience.

  17. Individual cylinder knock control by detecting cylinder pressure

    SciTech Connect

    Sawamoto, K.; Kawamura, Y.; Kita, T.; Matsushita, K.

    1987-01-01

    To improve available power, tolerance to variation in fuel octane number and high engine speed knock control, an individual cylinder knock control has been developed. Knock are detected by spark plug washer transducers, which indicate individual cylinder pressures.) Last year the authors read a paper entitled ''Cylinder Pressure Vibration Analysis Indicates Accurate Knock Detection''. They read continuously on the following items. Spark plug washer transducers - These are piezoelectric ceramic rings which fit beneath individual spark plugs. These can detect knock at high engine speed, and are very durable. Knock detection and control algorithm - Knock is indicated by the transducer's cylinder pressure vibration signal. When knock occurs in the cylinder, the ignition timing of the cylinder is controlled. During the transient condition, control response is fast by learning control. Fail safe - At transducer trouble, the ignition timing of the cylinder is controlled by other transducer signals. Electric control unit - It is included in NISSANs Electronic Concentrated Engine Control System (ECCS). Effects of this control - It improved WOT torque by 7-15%, torelance to variation in fuel octane number, and high engine speed control performance.

  18. 40 CFR 205.171-8 - Passing or failing under SEA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Passing or failing under SEA. 205.171... Passing or failing under SEA. (a) A failing exhaust system is one which, when installed on any motorcycle... standard in § 205.166. (b) The number of failing vehicles in a sample determines whether the sample...

  19. 40 CFR 1068.420 - How do I know when my engine family fails an SEA?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... fails an SEA? 1068.420 Section 1068.420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Auditing § 1068.420 How do I know when my engine family fails an SEA? (a) A failed engine or piece of... pollutants or a fail decision for one pollutant. (c) You reach a pass decision for the SEA requirements...

  20. Fuel dissipater for pressurized fuel cell generators

    DOEpatents

    Basel, Richard A.; King, John E.

    2003-11-04

    An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a pressurized fuel cell generator (10) when the electrical power output of the fuel cell generator is terminated during transient operation, such as a shutdown; where, two electrically resistive elements (two of 28, 53, 54, 55) at least one of which is connected in parallel, in association with contactors (26, 57, 58, 59), a multi-point settable sensor relay (23) and a circuit breaker (24), are automatically connected across the fuel cell generator terminals (21, 22) at two or more contact points, in order to draw current, thereby depleting the fuel inventory in the generator.

  1. The effect of fuel type in unsaturated spent fuel tests

    SciTech Connect

    Finn, P.A.; Gong, M.; Bates, J.K.; Emery, J.W.; Hoh, J.C.

    1994-04-01

    Two well-characterized types of spent nuclear fuel (ATM-103 and ATM-106) were tested under simulated unsaturated conditions with simulated groundwater at 90{degree}C. The actinides present in the leachate were measured after periods of approximately 60, 120, and 275 days. The vessels were acid stripped after 120 and 275 days. Both colloidal and soluble actinide species were detected in the leachates which had pHs ranging from 4 to 7. Alpha spectroscopy studies of filtered and unfiltered leachates showed that large amounts of actinides may be bound in colloids. The uranium phases identified in the colloids were schoepite and soddyite. The actinide release behavior of the two fuels appears to be different. The ATM-106 fuel began to release actinides later than the ATM-103 fuel, but after 275 days, it had released more. The amount of americium released from the two fuels was a higher percentage of the maximum amount of americium present than was the percentage of the simultaneous amount of uranium released.

  2. Disks around Failed Stars - a Question of Age

    NASA Astrophysics Data System (ADS)

    2002-08-01

    First Ground-Based Mid-Infrared Observations of Brown Dwarfs [1] Summary A team of European astronomers [2] have observed eight Brown Dwarfs, i.e., small and faint objects also known as "failed stars", with the TIMMI2 infrared sensitive instrument at the ESO 3.6-m telescope on La Silla. From two of these, mid-infrared radiation is detected - for the first time ever from such objects with a ground-based telescope . While the younger Brown Dwarf, aged a few million years, is found to be surrounded by a dusty disk, no warm dust is present around the older ones. The new observations support the following formation hypothesis for Brown Dwarfs: they are born in the same way as "real" stars, by contraction in interstellar clouds of gas and dust . During the later stages of this process, the infalling material is transferred onto the star via a gas and dust disk . This disk - in which planets may possibly form - then disperses with time. PR Photo 17a/02 : Image of Brown Dwarf LP 944-20 PR Photo 17b/02 : Models of the disk around Brown Dwarf Cha HA 2 Brown Dwarfs are faint and cool objects Astronomical objects known as "Brown Dwarfs" are "failed stars" . Their comparatively small mass, less than about 7% of that of our Sun (or about 75 times the mass of planet Jupiter), is too small to achieve sufficiently high pressure and temperature at their centre to ignite energy-producing nuclear processes. Some astronomers also refer to Brown Dwarfs as a "missing link" between planets and stars, being neither one nor the other, yet with similarities to both. They do not burn hydrogen to helium as "real" stars do, but continue to emit faint light as they slowly contract and cool during millions of years. They end their inglorious life with a whimper and finally fade into eternal insignificance. Although Brown Dwarfs were theoretically predicted already in 1963, astronomers had to wait until 1995 for the first one to be discovered. This was mainly due to their extreme faintness as

  3. 40 CFR 80.8 - Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fuel, fuel additives, and renewable fuels. 80.8 Section 80.8 Protection of Environment ENVIRONMENTAL... Provisions § 80.8 Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels. The..., blendstocks, fuel additives and renewable fuels for purposes of determining compliance with the...

  4. Beneficial effects of SR33805 in failing myocardium

    PubMed Central

    Ait Mou, Younss; Toth, Attila; Cassan, Cécile; Czuriga, Daniel; de Tombe, Pieter P.; Papp, Zoltan; Lacampagne, Alain; Cazorla, Olivier

    2011-01-01

    Aims SR33805, a potent Ca2+ channel blocker, increases cardiac myofilament Ca2+ sensitivity in healthy rat cardiomyocytes. Therefore, the aim of the present study was to evaluate the effects of SR33805 on contractile properties in ischaemic failing hearts after myocardial infarction (MI) in vivo and in vitro at the cellular level. Methods and results The effect of SR33805 (10 µM) was tested on the excitation–contraction coupling of cardiomyocytes isolated from rat with end-stage heart failure. Cell shortening and Ca2+ transients were measured in intact cardiomyocytes, while contractile properties were determined in Triton X-100 permeabilized myocytes. Acute treatment with SR33805 restored the MI-altered cell shortening without affecting the Ca2+ transient amplitude, suggesting an increase of myofilament Ca2+ sensitivity in MI myocytes. Indeed, a SR33805-induced sensitization of myofilament activation was found to be associated with a slight increase in myosin light chain-2 phosphorylation and a more significant decrease on troponin I (TnI) phosphorylation. Decreased TnI phosphorylation was related to inhibition of protein kinase A activity by SR33805. Finally, administration of a single intra-peritoneal bolus of SR33805 (20 mg/kg) improved end-systolic strain and fractional shortening of MI hearts. Conclusion The present study indicates that treatment with SR33805 improved contractility of ischaemic failing hearts after MI in the rat by selectively modulating the phosphorylation status of sarcomeric regulatory proteins, which then sensitized the myofilaments to Ca2+. Our results gave a proof of concept that manipulation of the Ca2+ sensitivity of sarcomeric regulatory proteins can be used to improve contractility of a failing heart. PMID:21467075

  5. Failed magmatic eruptions: Late-stage cessation of magma ascent

    USGS Publications Warehouse

    Moran, S.C.; Newhall, C.; Roman, D.C.

    2011-01-01

    When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: "deep intrusion", "shallow intrusion", "sluggish/viscous magmatic eruption", and "rapid, often explosive magmatic eruption". We define "failed eruptions" as instances in which magma reaches but does not pass the "shallow intrusion" stage, i. e., when magma gets close to, but does not reach, the surface. Competing factors act to promote or hinder the eventual eruption of a magma intrusion. Fresh intrusion from depth, high magma gas content, rapid ascent rates that leave little time for enroute degassing, opening of pathways, and sudden decompression near the surface all act to promote eruption, whereas decreased magma supply from depth, slow ascent, significant enroute degassing and associated increases in viscosity, and impingement on structural barriers all act to hinder eruption. All of these factors interact in complex ways with variable results, but often cause magma to stall at some depth before reaching the surface. Although certain precursory phenomena, such as rapidly escalating seismic swarms or rates of degassing or deformation, are good indicators that an eruption is likely, such phenomena have also been observed in association with intrusions that have ultimately failed to erupt. A perpetual difficulty with quantifying the probability of eruption is a lack of data, particularly on instances of failed eruptions. This difficulty is being addressed in part through the WOVOdat database. Papers in this volume will be an additional resource for scientists grappling with the issue of whether or not an episode of unrest will lead to a magmatic eruption.

  6. Apparatus for mixing fuel in a gas turbine nozzle

    SciTech Connect

    Barker, Carl Robert

    2016-11-22

    A fuel nozzle in a combustion turbine engine that includes: a fuel plenum defined between an circumferentially extending shroud and axially by a forward tube-sheet and an aft tube-sheet; and a mixing-tube that extends across the fuel plenum that defines a passageway connecting an inlet formed through the forward tube-sheet and an outlet formed through the aft tube-sheet, the mixing-tube comprising one or more fuel ports that fluidly communicate with the fuel plenum. The mixing-tube may include grooves on an outer surface, and be attached to the forward tube-sheet by a connection having a fail-safe leakage path.

  7. Fired worker fails to meet ADA's 'regarded as' test.

    PubMed

    1998-08-07

    [Name removed], a waiter at a Long Island [name removed], claimed that he was fired based on the misconception that because he was gay, he was HIV-positive. [Name removed] sued under the Federal Rehabilitation Act and the Americans with Disabilities Act, because there is not a law in NY that protects people from discrimination based on sexual orientation. The court rejected his claim by saying that he failed to provide a factual basis for his allegations. The employers stated that they fired [name removed] for using profanity toward a coworker, while on the job.

  8. Sjögren Syndrome: Why Do Clinical Trials Fail?

    PubMed

    Fox, Robert I; Fox, Carla M

    2016-08-01

    Sjögren syndrome (SS) comprises glandular and extraglandular manifestations. Double-blind prospective trials of traditional disease-modifying antirheumatic drugs and biologics have failed because they have not improved benign symptoms, the major cause of lowered quality of life. Rituximab has proven effective in SS patients with associated mixed cryoglobulinemia, parotid gland swelling, lymphocytic interstitial pneumonitis, thrombocytopenia, and other manifestations. There were few of these SS patients in the trials required for FDA approval. Most patients had benign symptoms and did not show benefit, leading to failure of the study. This article examines the reasons for these failures and proposes future directions.

  9. Surgical management of vestibular schwannomas after failed radiation treatment.

    PubMed

    Nonaka, Yoichi; Fukushima, Takanori; Watanabe, Kentaro; Friedman, Allan H; Cunningham, Calhoun D; Zomorodi, Ali R

    2016-04-01

    Increasing numbers of patients with vestibular schwannoma (VS) have been treated with focused-beam stereotactic radiation treatment (SRT) including Gamma knife, CyberKnife, X-knife, Novalis, or proton beam therapy. The purpose of this study was to document the incidence of tumor regrowth or symptoms that worsened or first developed following SRT and to discuss surgical strategies for patients who have failed SRT for VS. A consecutive series of 39 patients with SRT failed VS were surgically treated. Clinical symptoms, tumor regrowth at follow-up, intraoperative findings, and surgical outcome were evaluated. There were 15 males and 24 females with a mean age of 51.8 years. Thirty-six patients (92.3%) demonstrated steady tumor growth after SRT. Two (5.1%) patients with slight increase of the mass underwent surgical resection because of development of unbearable facial pain. Symptoms that worsened or newly developed following SRT in this series were deafness (41%), dizziness (35.9%), facial numbness (25.6%), tinnitus (20.5%), facial nerve palsy (7.7%), and facial pain (7.7%). Intraoperative findings demonstrated fibrous changes of the tumor mass, cyst formation, and brownish-yellow or purple discoloration of the tumor capsule. Severe adhesions between the tumor capsule and cranial nerves, vessels, and the brainstem were observed in 69.2%. Additionally, the facial nerve was more fragile and irritable in all cases. Gross total resection (GTR) was achieved in 33.3% of patients, near-total resection (NTR) in 35.9%, and subtotal resection (STR) in 30.8% of patients. New facial nerve palsy was seen in seven patients (19.4%) postoperatively. Our findings suggest that patients with VS who fail SRT with either tumor progression or worsening of clinical symptoms will have an increased rate of adhesions to the neurovascular structures and may have radiation-influenced neuromalacia. Salvage surgery of radiation-failed tumors is more difficult and will have a higher risk of

  10. Improved Quick Disconnect (QD) Interface Through Fail Safe Parts Identification

    NASA Technical Reports Server (NTRS)

    Blanch-Payne, Evelyn

    2001-01-01

    An extensive review of existing Quick Disconnects (QDs) mating and demating operations was performed to determine which shuttle part interface identifications and procedures contribute to human factor errors. The research methods used consisted of interviews with engineers and technicians, examination of incident reports, critiques of video and audio tapes of QD operations, and attendance of a Hyper QD operational course. The data strongly suggests that there are inherit human factor errors involved in QD operations. To promote fail-safe operations, QD interface problem areas and recommendations were outlined and reviewed. It is suggested that dialogue, investigations and recommendations continue.

  11. Analysis of failed ramps during the RHIC FY09 run

    SciTech Connect

    Minty, M.

    2014-08-15

    The Relativistic Heavy Ion Collider (RHIC) is a versatile accelerator that supports operation with polarized protons of up to 250 GeV and ions with up to 100 GeV/nucleon. During any running period, various operating scenarios with different particle species, beam energies or accelerator optics are commissioned. In this report the beam commissioning periods for establishing full energy beams (ramp development periods) from the FY09 run are summarized and, for the purpose of motivating further developments, we analyze the reasons for all failed ramps.

  12. FUEL ROD CLUSTERS

    DOEpatents

    Schultz, A.B.

    1959-08-01

    A cluster of nuclear fuel rods and a tubular casing therefor through which a coolant flows in heat-exchange contact with the fuel rods is described. The fuel rcds are held in the casing by virtue of the compressive force exerted between longitudinal ribs of the fuel rcds and internal ribs of the casing or the internal surfaces thereof.

  13. SULFUR REMOVAL FROM PIPE LINE NATURAL GAS FUEL: APPLICATION TO FUEL CELL POWER GENERATION SYSTEMS

    SciTech Connect

    King, David L.; Birnbaum, Jerome C.; Singh, Prabhakar

    2003-11-21

    Pipeline natural gas is being considered as the fuel of choice for utilization in fuel cell-based distributed generation systems because of its abundant supply and the existing supply infrastructure (1). For effective utilization in fuel cells, pipeline gas requires efficient removal of sulfur impurities (naturally occurring sulfur compounds or sulfur bearing odorants) to prevent the electrical performance degradation of the fuel cell system. Sulfur odorants such as thiols and sulfides are added to pipeline natural gas and to LPG to ensure safe handling during transportation and utilization. The odorants allow the detection of minute gas line leaks, thereby minimizing the potential for explosions or fires.

  14. Concentric layer ramjet fuel

    SciTech Connect

    Burdette, G.W.; Francis, J.P.

    1988-03-08

    This patent describes a solid fuel ramjet grain comprising concentric layers of solid ramjet fuel having a perforation therethrough along the center axis of the grain. The performation is connected to a combustion after-chamber. The solid ramjet fuel layers comprises a pure hydroxyl-terminated polybutadiene hydrocarbon fuel or a mixture of a hydroxyl-terminated polybutadiene hydrocarbon fuel and from about 5 to about 60 percent by weight of an additive to increase the fuel regression rate selected from the group consisting of magnesium, boron carbide, aluminum, and zirconium such that, when buried in the operation of the ramjet, each fuel layer produces a different level of thrust.

  15. Fuel transfer system

    DOEpatents

    Townsend, H.E.; Barbanti, G.

    1994-03-01

    A nuclear fuel bundle fuel transfer system includes a transfer pool containing water at a level above a reactor core. A fuel transfer machine therein includes a carriage disposed in the transfer pool and under the water for transporting fuel bundles. The carriage is selectively movable through the water in the transfer pool and individual fuel bundles are carried vertically in the carriage. In a preferred embodiment, a first movable bridge is disposed over an upper pool containing the reactor core, and a second movable bridge is disposed over a fuel storage pool, with the transfer pool being disposed therebetween. A fuel bundle may be moved by the first bridge from the reactor core and loaded into the carriage which transports the fuel bundle to the second bridge which picks up the fuel bundle and carries it to the fuel storage pool. 6 figures.

  16. Fuel transfer system

    DOEpatents

    Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A nuclear fuel bundle fuel transfer system includes a transfer pool containing water at a level above a reactor core. A fuel transfer machine therein includes a carriage disposed in the transfer pool and under the water for transporting fuel bundles. The carriage is selectively movable through the water in the transfer pool and individual fuel bundles are carried vertically in the carriage. In a preferred embodiment, a first movable bridge is disposed over an upper pool containing the reactor core, and a second movable bridge is disposed over a fuel storage pool, with the transfer pool being disposed therebetween. A fuel bundle may be moved by the first bridge from the reactor core and loaded into the carriage which transports the fuel bundle to the second bridge which picks up the fuel bundle and carries it to the fuel storage pool.

  17. Fuel cells seminar

    SciTech Connect

    1996-12-01

    This year`s meeting highlights the fact that fuel cells for both stationary and transportation applications have reached the dawn of commercialization. Sales of stationary fuel cells have grown steadily over the past 2 years. Phosphoric acid fuel cell buses have been demonstrated in urban areas. Proton-exchange membrane fuel cells are on the verge of revolutionizing the transportation industry. These activities and many more are discussed during this seminar, which provides a forum for people from the international fuel cell community engaged in a wide spectrum of fuel cell activities. Discussions addressing R&D of fuel cell technologies, manufacturing and marketing of fuel cells, and experiences of fuel cell users took place through oral and poster presentations. For the first time, the seminar included commercial exhibits, further evidence that commercial fuel cell technology has arrived. A total of 205 papers is included in this volume.

  18. Detection of fuel release in a nuclear accident: a method for preconcentration and isolation of reactor-borne (239)Np using ion-specific extraction chromatography.

    PubMed

    Rosenberg, Brett L; Shozugawa, Katsumi; Steinhauser, Georg

    2015-09-01

    Although actinides are the most informative elements with respect to the nature of a nuclear accident, plutonium analysis is complicated by the background created by fallout from atmospheric nuclear explosions. Therefore, we propose (239)Np, a short-lived actinide that emits several γ rays, as a preferred proxy. The aim of this study was to screen ion specific extraction chromatography resins (RE-, TEVA-, UTEVA-, TRU-, and Actinide-Resin) for the highest possible recovery and separation of trace amounts of (239)Np from samples with large activities of fission products such as radiocesium, radioiodine, and, most importantly, radiotellurium, the latter of which causes spectral interference in gamma spectrometry through overlapping peaks with (239)Np. The investigated environmental media for these separations were aqueous solutions simulating rainwater and soil. Spiked samples containing (239)Np and the aforementioned volatile radionuclides were separated through extraction chromatographic columns to ascertain the most effective means of separating (239)Np from other fission products for detection by gamma spectroscopy. We propose a method for nuclear accident preparedness based on the use of Eichrom's RE-Resin. The proposed method was found most effective for isolating (239)Np from interfering radionuclides in both aqueous solution and soil using 8 M HNO3 as the loading solution and H2O as the eluent. The RE-Resin outperforms the more commonly used TEVA-Resin because the TEVA-Resin showed a higher affinity for interfering radiotellurium and radioiodine.

  19. In situ repair of a failed compression fitting

    DOEpatents

    Wolbert, R.R.; Jandrasits, W.G.

    1985-08-05

    A method and apparatus for the in situ repair of a failed compression fitting is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

  20. In situ repair of a failed compression fitting

    DOEpatents

    Wolbert, Ronald R.; Jandrasits, Walter G.

    1986-01-01

    A method and apparatus for the in situ repair of a failed compression fitg is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

  1. A PKM2 signature in the failing heart

    PubMed Central

    Rees, Meredith L.; Subramaniam, Janani; Li, Yuanteng; Hamilton, Dale J.; Frazier, O. Howard; Taegtmeyer, Heinrich

    2015-01-01

    A salient feature of the failing heart is metabolic remodeling towards predominant glucose metabolism and activation of the fetal gene program. Sunitinib is a multitargeted receptor tyrosine kinase inhibitor used for the treatment of highly vascularized tumors. In diabetic patients, sunitinib significantly decreases blood glucose. However, a considerable proportion of sunitinib-treated patients develop cardiac dysfunction or failure. We asked whether sunitinib treatment results in shift towards glycolysis in the heart. Glucose uptake by the heart was increased fivefold in mice treated with sunitinib. Transcript analysis by qPCR revealed an induction of genes associated with glycolysis and reactivation of the fetal gene program. Additionally, we observed a shift in the enzyme pyruvate kinase from the adult M1 (PKM1) isoform to the fetal M2 (PKM2) isoform, a hallmark of the Warburg Effect. This novel observation led us to examine whether a similar shift occurs in human heart failure. Examination of tissue from patients with heart failure similarly displayed an induction of PKM2. Moreover, this phenomenon was partially reversed following mechanical unloading. We propose that pyruvate kinase isoform switching represents a novel feature of the fetal gene program in the failing heart. PMID:25735978

  2. Resection Interposition Arthroplasty for Failed Distal Ulna Resections

    PubMed Central

    Papatheodorou, Loukia K.; Rubright, James H.; Kokkalis, Zinon T.; Sotereanos, Dean G.

    2013-01-01

    The major complications of distal ulna resection, the Darrach procedure, are radioulnar impingement and instability. High failure rates have been reported despite published modifications of the Darrach procedure. Several surgical techniques have been developed to treat this difficult problem and to mitigate the symptoms associated with painful convergence and impingement. No technique has demonstrated clinical superiority. Recently, implant arthroplasty of the distal ulna has been endorsed as an option for the management of the symptomatic patient with a failed distal ulna resection. However, there are concerns for implant longevity, especially in young, active adults. Resection interposition arthroplasty relies on interposition of an Achilles tendon allograft between the distal radius and the resected distal ulna. Although this technique does not restore normal mechanics of the distal radioulnar joint, it can prevent painful convergence of the radius on the ulna. Achilles allograft interposition arthroplasty is a safe and highly effective alternative for failed distal ulna resections, especially for young, active patients, in whom an implant or alternative procedure may not be appropriate. PMID:24436784

  3. Untrained Chimpanzees (Pan troglodytes schweinfurthii) Fail to Imitate Novel Actions

    PubMed Central

    Tennie, Claudio; Call, Josep; Tomasello, Michael

    2012-01-01

    Background Social learning research in apes has focused on social learning in the technical (problem solving) domain - an approach that confounds action and physical information. Successful subjects in such studies may have been able to perform target actions not as a result of imitation learning but because they had learnt some technical aspect, for example, copying the movements of an apparatus (i.e., different forms of emulation learning). Methods Here we present data on action copying by non-enculturated and untrained chimpanzees when physical information is removed from demonstrations. To date, only one such study (on gesture copying in a begging context) has been conducted – with negative results. Here we have improved this methodology and have also added non-begging test situations (a possible confound of the earlier study). Both familiar and novel actions were used as targets. Prior to testing, a trained conspecific demonstrator was rewarded for performing target actions in view of observers. All but one of the tested chimpanzees already failed to copy familiar actions. When retested with a novel target action, also the previously successful subject failed to copy – and he did so across several contexts. Conclusion Chimpanzees do not seem to copy novel actions, and only some ever copy familiar ones. Due to our having tested only non-enculturated and untrained chimpanzees, the performance of our test subjects speak more than most other studies of the general (dis-)ability of chimpanzees to copy actions, and especially novel actions. PMID:22905102

  4. Combination therapy for salvaging a failing, experimental skin flap.

    PubMed

    Shah, D K; Zhang, W X; Forman, D L; Prabhat, A; Urken, M L; Weinberg, H

    1996-08-01

    The failing free flap remains a major problem for the reconstructive surgeon. Many and varied pharmacologic agents have been utilized to reverse the effects of ischemia in these flaps. Treatments have been aimed at inhibiting presumed causative factors in the no-reflow phenomenon. Therapy has generally been single in nature and designed to affect only one of these presumed factors. In this study, several pharmacologic agents were utilized individually or in combination therapy as postischemic washouts, in an effort to attack the multiple causative factors in the no-reflow phenomenon and to improve flap survival in a rat abdominal skin flap model. The treatment agents included lactated Ringer's, superoxide dismutase, and urokinase, with each used independently as a postischemic perfusion washout. Combination therapy utilized an initial postischemic perfusion with urokinase, followed by a second perfusion washout with superoxide dismutase. After 18 hr of primary ischemia, there was increased flap survival in the animals undergoing perfusion washout with either superoxide dismutase alone or with combined urokinase and superoxide dismutase washouts, compared to all other treatments (p < 0.001). It was found that flaps undergoing combined urokinase and superoxide dismutase postischemic perfusion washouts demonstrated significantly improved survival after 20 hr of primary ischemia, compared to all other therapies (p < 0.05). By demonstrating improved survival when a thrombolytic agent is used in conjunction with an oxygen free radical scavenger, these findings may have implications in the treatment of clinically failing free flaps.

  5. Stress and Diffusion in Stored Pu ZPPR Fuel from Alpha Generation

    SciTech Connect

    Charles W. Solbrig; Chad L. Pope; Jason P. Andrus

    2014-07-01

    ZPPR (Zero Power Physics Reactor) is a research reactor that has been used to investigate breeder reactor fuel designs. The reactor has been dismantled but its fuel is still stored there. Of concern are its plutonium containing metal fuel elements which are enclosed in stainless steel cladding with gas space filled with helium–argon gas and welded air tight. The fuel elements which are 5.08 cm by 0.508 cm up to 20.32 cm long (2 in × 0.2 in × 8 in) were manufactured in 1968. A few of these fuel elements have failed releasing contamination raising concern about the general state of the large number of other fuel elements. Inspection of the large number of fuel elements could lead to contamination release so analytical studies have been conducted to estimate the probability of failed fuel elements. This paper investigates the possible fuel failures due to generation of helium in the metal fuel from the decay of Pu and its possible damage to the fuel cladding from metal fuel expansion or from diffusion of helium into the fuel gas space. This paper (1) calculates the initial gas loading in a fuel element and its internal free volume after it has been brought into the atmosphere at ZPPR, (2) shows that the amount of helium generated by decay of Pu over 46 years since manufacture is significantly greater than this initial loading, (3) determines the amount of fuel swelling if the helium stays fixed in the fuel plate and estimates the amount of helium which diffuses out of the fuel plate into the fuel plenum assuming the helium does not remain fixed in the fuel plate but can diffuse to the plenum and possibly through the cladding. Since the literature is not clear as to which possibility occurs, as with Schroedinger’s cat, both possibilities are analyzed. The paper concludes that (1) if the gas generated is fixed in the fuel, then the fuel swelling it can cause would not cause any fuel failure and (2) if the helium does diffuse out of the fuel (in accordance

  6. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  7. Volatile species retention during metallic fuel casting

    NASA Astrophysics Data System (ADS)

    Fielding, Randall S.; Porter, Douglas L.

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  8. Alternative aircraft fuels

    NASA Technical Reports Server (NTRS)

    Longwell, J. P.; Grobman, J.

    1978-01-01

    In connection with the anticipated impossibility to provide on a long-term basis liquid fuels derived from petroleum, an investigation has been conducted with the objective to assess the suitability of jet fuels made from oil shale and coal and to develop a data base which will allow optimization of future fuel characteristics, taking energy efficiency of manufacture and the tradeoffs in aircraft and engine design into account. The properties of future aviation fuels are examined and proposed solutions to problems of alternative fuels are discussed. Attention is given to the refining of jet fuel to current specifications, the control of fuel thermal stability, and combustor technology for use of broad specification fuels. The first solution is to continue to develop the necessary technology at the refinery to produce specification jet fuels regardless of the crude source.

  9. Fuel injector system

    DOEpatents

    Hsu, Bertrand D.; Leonard, Gary L.

    1988-01-01

    A fuel injection system particularly adapted for injecting coal slurry fuels at high pressures includes an accumulator-type fuel injector which utilizes high-pressure pilot fuel as a purging fluid to prevent hard particles in the fuel from impeding the opening and closing movement of a needle valve, and as a hydraulic medium to hold the needle valve in its closed position. A fluid passage in the injector delivers an appropriately small amount of the ignition-aiding pilot fuel to an appropriate region of a chamber in the injector's nozzle so that at the beginning of each injection interval the first stratum of fuel to be discharged consists essentially of pilot fuel and thereafter mostly slurry fuel is injected.

  10. Dual Tank Fuel System

    DOEpatents

    Wagner, Richard William; Burkhard, James Frank; Dauer, Kenneth John

    1999-11-16

    A dual tank fuel system has primary and secondary fuel tanks, with the primary tank including a filler pipe to receive fuel and a discharge line to deliver fuel to an engine, and with a balance pipe interconnecting the primary tank and the secondary tank. The balance pipe opens close to the bottom of each tank to direct fuel from the primary tank to the secondary tank as the primary tank is filled, and to direct fuel from the secondary tank to the primary tank as fuel is discharged from the primary tank through the discharge line. A vent line has branches connected to each tank to direct fuel vapor from the tanks as the tanks are filled, and to admit air to the tanks as fuel is delivered to the engine.

  11. [Multimodal therapy concepts for failed back surgery syndrome].

    PubMed

    Casser, Hans-Raimund

    2016-09-01

    Failed back surgery syndrome (FBSS) is a frequent complication (15-40 %) of lumbar disc surgery and is rarely successfully treated by surgery with the exception of a re-prolapse associated with radicular pain. Multimodal pain treatment, however, is indicated by a lack of pathoanatomical correlates, unclear cause and psychosocial risk factors.This review describes a standardized non-operative treatment starting with broad interdisciplinary clarification by medical, psychological and physiotherapeutic means (assessment).If the conditions for multimodal pain therapy are met, the OPS 8‑918-procedure can be applied to avoid chronic developing pain. In doing so, the already issued quality standards and guidelines for documentation should be respected.

  12. Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies

    PubMed Central

    Sanchis-Alfonso, Vicente; Montesinos-Berry, Erik; Ramirez-Fuentes, Cristina; Leal-Blanquet, Joan; Gelber, Pablo E; Monllau, Joan Carles

    2017-01-01

    Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical indication or inappropriate surgical technique/patient selection; (2) a technical error; and (3) an incorrect assessment of the concomitant risk factors for instability. An understanding of the anatomy and biomechanics of the MPFL and cautiousness with the imaging techniques while favoring clinical over radiological findings and the use of common sense to determine the adequate surgical technique for each particular case, are critical to minimizing MPFL surgery failure. Additionally, our approach to dealing with failure after primary MPFL reconstruction is also presented. PMID:28251062

  13. Why did ISO 9001:2008 system fail to deliver?

    PubMed

    Langford, Melvyn

    2014-02-01

    This article is based on an actual investigation undertaken, and summarises the subsequent report's findings and observations. It has been anonymised for obvious reasons. In May 2013 an analysis was undertaken by a multidisciplinary team that compared an NHS Trust estates department's managerial systems against the NHS national recommendations. The conclusions stated that: 'There was a systemic failure across a large number of topics generating intolerable/substantial risks to the organisation, its staff, and patients; this despite the department's managerial systems being accredited to the International Standard ISO 9001:2008'. The natural question raised when presented with this demonstrable and auditable evidence was: 'Why did the ISO 9001:2008 system fail?'

  14. Failed back surgery syndrome: a suggested algorithm of care

    PubMed Central

    Ganty, Praveen

    2012-01-01

    Failed back surgery syndrome (FBSS) is a complex condition which can be very difficult to treat. In this article, we propose a pragmatic algorithm for the management of the syndrome. The management of this condition should include a comprehensive initial assessment to rule out treatable cause, pharmacological optimisation, psychological techniques and neuromodulation. There is good evidence to support early application of conventional spinal cord stimulation for FBSS patients suffering from predominant buttock and leg pain. Emerging techniques in neuromodulation such as high-frequency spinal cord stimulation, peripheral nerve field stimulation and dorsal root ganglion stimulation hold promise for the future, but long-term outcome regarding efficacy and safety is not yet established. Intrathecal drug delivery systems should also be considered in those who are unsuitable or unresponsive to neuromodulation and still warrant further treatment. However, the long-term outcome may not be as good as with other treatments mentioned above. PMID:26516487

  15. Recanalization of failed autogenous conduit utilizing laser revascularization.

    PubMed

    Chander, Rajiv K; Oza, Parind; Patel, Mayank; Balar, Nilesh

    2011-10-01

    The traditional approach for the treatment of restenosis of autogenous vein bypass has been revision of bypass with vein patch angioplasty, interposition jump graft, or thrombectomy procedures for those patients with extensive occlusive disease and limb-threatening ischemia. Endovascular intervention traditionally involves angioplasty of the graft; however, vessels with diffuse disease or extensive longitudinal lesions are generally difficult to revascularize utilizing this technique. Surgical revision of a threatened autogenous vein graft may carry a morbidity rate as high as 13.6%. We present a series of cases in which excimer laser atherectomy (LA) was used to recanalize an occluded autogenous saphenous vein bypass. Of the occluded vein bypasses failed angioplasty and were successfully atherectomized with LA measuring lengths of 35 and 30 cm, respectively. The infrainguinal has a 6-month follow-up, while the infragencular has a follow-up of 1 year, with resolution of presenting symptoms.

  16. Unaware person recognition from the body when face identification fails.

    PubMed

    Rice, Allyson; Phillips, P Jonathon; Natu, Vaidehi; An, Xiaobo; O'Toole, Alice J

    2013-11-01

    How does one recognize a person when face identification fails? Here, we show that people rely on the body but are unaware of doing so. State-of-the-art face-recognition algorithms were used to select images of people with almost no useful identity information in the face. Recognition of the face alone in these cases was near chance level, but recognition of the person was accurate. Accuracy in identifying the person without the face was identical to that in identifying the whole person. Paradoxically, people reported relying heavily on facial features over noninternal face and body features in making their identity decisions. Eye movements indicated otherwise, with gaze duration and fixations shifting adaptively toward the body and away from the face when the body was a better indicator of identity than the face. This shift occurred with no cost to accuracy or response time. Human identity processing may be partially inaccessible to conscious awareness.

  17. Behavior of Puerto Rican parrots during failed nesting attempts

    USGS Publications Warehouse

    Wilson, K.A.; Wilson, M.H.; Field, R.

    1997-01-01

    We compared patterns of nesting behavior of four pairs of Puerto Rican Parrots (Amazona vittata) that experienced failed nesting attempts to behavior of four pairs of parrots that experienced no substantial nest problems and successfully fledged young without management intervention. Only changes in female parrots' behavior were clearly associated with nest failure. During incubation, decreases in nest attendance, increases in duration of recesses, and increases in frequency of nest entries by female parrots were associated with imminent abandonment of nests. During early chick rearing, similar behavior was associated with the loss of broods. Low nest attendance and long recesses by female parrots during incubation were also associated with successful hatching of eggs followed by death of young several days later. The behavior patterns and changes in Puerto Rican Parrot nesting behavior described in this paper may alert biologists to nest problems that might be mitigated by management intervention.

  18. Setting the Clock for Fail-Safe Early Embryogenesis

    NASA Astrophysics Data System (ADS)

    Fickentscher, Rolf; Struntz, Philipp; Weiss, Matthias

    2016-10-01

    The embryogenesis of the small nematode Caenorhabditis elegans is a remarkably robust self-organization phenomenon. Cell migration trajectories in the early embryo, for example, are well explained by mechanical cues that push cells into positions where they experience the least repulsive forces. Yet, how this mechanically guided progress in development is properly timed has remained elusive so far. Here, we show that cell volumes and division times are strongly anticorrelated during the early embryogenesis of C. elegans with significant differences between somatic cells and precursors of the germline. Our experimental findings are explained by a simple model that in conjunction with mechanical guidance can account for the fail-safe early embryogenesis of C. elegans.

  19. Optimised to Fail: Card Readers for Online Banking

    NASA Astrophysics Data System (ADS)

    Drimer, Saar; Murdoch, Steven J.; Anderson, Ross

    The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

  20. Hyperbaric oxygen (HBO2) treatment for a failing facial flap.

    PubMed

    McCrary, Brian F

    2007-01-01

    Hyperbaric oxygen (HBO2) is an approved treatment for 13 pathological entities. One of these indications--a failing facial flap--is presented in this case report of a traumatic wound to the face and right axilla after an unprovoked pit bull attack on a 4 year old girl. Surgical repair was started acutely but the facial flap became congested and ischaemic, indicating deterioration of the blood supply. HBO2 treatments were initiated twice a day, resulting in remarkably decreased swelling and discomfort after the first treatment. Leeching was also used to assist with reduction of venous congestion in the flap. The patient was discharged 5 days later with a well perfused, mostly intact, incision with minimal tenderness. Surgical repair was required for a small area of wound dehiscence. Photographs documenting the patient's progress with HBO2 are presented. A discussion of the mechanisms of action of HBO2 and its beneficial effects is provided in this case.

  1. Thrill of Victory or Agony of Defeat? Perceivers Fail to Utilize Information in Facial Movements

    PubMed Central

    Aviezer, Hillel; Messinger, Daniel S.; Zangvil, Shiri; Mattson, Whitney I.; Gangi, Devon N.; Todorov, Alexander

    2015-01-01

    Although the distinction between positive and negative facial expressions is assumed to be clear and robust, recent research with intense real-life faces has shown that viewers are unable to reliably differentiate the valence of such expressions (Aviezer, Trope, & Todorov, 2012). Yet, the fact that viewers fail to distinguish these expressions does not in itself testify that the faces are physically identical. In experiment 1, the muscular activity of victorious and defeated faces was analyzed. Higher numbers of individually coded facial actions—particularly smiling and mouth opening—were more common among winners than losers, indicating an objective difference in facial activity. In experiment 2, we asked whether supplying participants with valid or invalid information about objective facial activity and valence would alter their ratings. Notwithstanding these manipulations, valence ratings were virtually identical in all groups and participants failed to differentiate between positive and negative faces. While objective differences between intense positive and negative faces are detectable, human viewers do not utilize these differences in determining valence. These results suggest a surprising dissociation between information present in expressions and information used by perceivers. PMID:26010575

  2. Fuel economy of hybrid fuel cell vehicles.

    SciTech Connect

    Ahluwalia, R.; Wang, X.; Rousseau, A.; Nuclear Engineering Division

    2004-01-01

    The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

  3. Failure detection and identification

    NASA Technical Reports Server (NTRS)

    Massoumnia, Mohammad-Ali; Verghese, George C.; Willsky, Alan S.

    1989-01-01

    Using the geometric concept of an unobservability subspace, a solution is given to the problem of detecting and identifying control system component failures in linear, time-invariant systems. Conditions are developed for the existence of a causal, linear, time-invariant processor that can detect and uniquely identify a component failure, first for the case where components can fail simultaneously, and then for the case where they fail only one at a time. Explicit design algorithms are provided when these conditions are satisfied. In addition to time-domain solvability conditions, frequency-domain interpretations of the results are given, and connections are drawn with results already available in the literature.

  4. Aircraft Integral Fuel Tank Corrosion Study

    DTIC Science & Technology

    2007-11-02

    sensor is formed by two concentric metallic electrodes, separated by an insulator material , between which an electric current circulates when a given... materials are used to make the mentioned current, proportional to the concentration of corrosive contaminants in the water and to the amount of microbial...contamination level, detected in the respective fuel tank. REFERENCES 1. C. B. Ward. Corrosion resulting from corrosion fuel tank contamination. Materials

  5. Fuel injection nozzle

    SciTech Connect

    Kato, M.; Tojo, S.; Arai, K.

    1986-07-22

    A fuel injection nozzle is described connected to a fuel injection pump to inject fuel into a combustion chamber of an internal combustion engine consisting of: a nozzle housing defining therein a fuel sump chamber, an injection hole communicating with the sump chamber and opened at the outer surface of the nozzle housing, a stepped cylinder bore having a smaller diameter bore section and a larger diameter bore section and a fuel passage communicating at one end with the sump chamber and at the other end with the smaller diameter bore section of the stepped cylinder bore; a stepped plunger fitted in the stepped cylinder bore and having a smaller diameter plunger section fitted into the smaller diameter bore section and a larger diameter plunger section fitted into the larger diameter bore section in which the smaller diameter bore section together with the end face of the smaller diameter plunger section defines a pump chamber communicating with the fuel passage and the larger diameter bore section together with the end face of the larger diameter plunger section defines a main fuel chamber into which a main fuel is supplied from the fuel injection pump; auxiliary fuel supply means for supplying an auxiliary fuel into the sump chamber and pump chamber through the fuel passage; valve means for opening and closing an injection hole; communication means for permitting the main fuel chamber to communicate with the fuel passage when the main fuel is supplied from the injection pump into the main fuel chamber to cause the stepped plunger to be moved a predetermined distance in a direction in which the auxiliary fuel in the pump chamber is pressurized.

  6. Fuel injection pump

    SciTech Connect

    Miyaki, M.

    1986-01-07

    This patent describes a fuel injection pump for delivering fuel to the cylinders of an internal combustion engine consisting of: a pump housing with a fuel chamber therein to which fuel is supplied from a fuel tank; means for compressing fuel in the pump chamber and delivering the compressed fuel to the engine cylinders with such means including a pump plunger adapted to be reciprocated so as to introduce fuel into the pump chamber and to pressurize the introduced fuel; spill means for spilling to a low-pressure side on a fuel tank side the compressed fuel which was pressurized in the pump chamber to be delivered from the pump chamber to the engine cylinders, the spill mechanism including a spill passage communicating with the pump chamber and including a solenoid valve located in the spill passage for opening and closing the spill passage with predetermined timing; escape for allowing the compressed fuel pressurized in the pump chamber to escape to the low-pressure side of the fuel tank side.

  7. Light-duty vehicle fuel economy improvements, 1979--1998: A consumer purchase model of corporate average fuel economy, fuel price, and income effects

    NASA Astrophysics Data System (ADS)

    Chien, David Michael

    2000-10-01

    The Energy Policy and Conservation Act of 1975, which created fuel economy standards for automobiles and light trucks, was passed by Congress in response to the rapid rise in world oil prices as a result of the 1973 oil crisis. The standards were first implemented in 1978 for automobiles and 1979 for light trucks, and began with initial standards of 18 MPG for automobiles and 17.2 MPG for light trucks. The current fuel economy standards for 1998 have been held constant at 27.5 MPG for automobiles and 20.5 MPG for light trucks since 1990--1991. While actual new automobile fuel economy has almost doubled from 14 MPG in 1974 to 27.2 MPG in 1994, it is reasonable to ask if the CAFE standards are still needed. Each year Congress attempts to pass another increase in the Corporate Average Fuel Economy (CAFE) standard and fails. Many have called for the abolition of CAFE standards citing the ineffectiveness of the standards in the past. In order to determine whether CAFE standards should be increased, held constant, or repealed, an evaluation of the effectiveness of the CAFE standards to date must be established. Because fuel prices were rising concurrently with the CAFE standards, many authors have attributed the rapid rise in new car fuel economy solely to fuel prices. The purpose of this dissertation is to re-examine the determinants of new car fuel economy via three effects: CAFE regulations, fuel price, and income effects. By measuring the marginal effects of the three fuel economy determinants upon consumers and manufacturers choices, for fuel economy, an estimate was made of the influence of each upon new fuel economy. The conclusions of this dissertation present some clear signals to policymakers: CAFE standards have been very effective in increasing fuel economy from 1979 to 1998. Furthermore, they have been the main cause of fuel economy improvement, with income being a much smaller component. Furthermore, this dissertation has suggested that fuel prices have

  8. Fuel cells and fuel cell catalysts

    DOEpatents

    Masel, Richard I.; Rice, Cynthia A.; Waszczuk, Piotr; Wieckowski, Andrzej

    2006-11-07

    A direct organic fuel cell includes a formic acid fuel solution having between about 10% and about 95% formic acid. The formic acid is oxidized at an anode. The anode may include a Pt/Pd catalyst that promotes the direct oxidation of the formic acid via a direct reaction path that does not include formation of a CO intermediate.

  9. Microscale Fuel Cells

    SciTech Connect

    Holladay, Jamie D.; Viswanathan, Vish V.

    2005-11-03

    Perhaprs some of the most innovative work on fuel cells has been the research dedicated to applying silicon fabrication techniques to fuel cells technology creating low power microscale fuel cells applicable to microelectro mechanical systems (MEMS), microsensors, cell phones, PDA’s, and other low power (0.001 to 5 We) applications. In this small power range, fuel cells offer the decoupling of the energy converter from the energy storage which may enable longer operating times and instant or near instant charging. To date, most of the microscale fuel cells being developed have been based on proton exchange membrane fuel cell technology (PEMFC) or direct methanol fuel cell (DMFC) technology. This section will discuss requirements and considerations that need to be addressed in the development of microscale fuel cells, as well as some proposed designs and fabrication strategies.

  10. FUEL CELL ELECTRODE MATERIALS

    DTIC Science & Technology

    FUEL CELL ELECTRODE MATERIALS. RAW MATERIAL SELECTION INFLUENCES POLARIZATION BUT IS NOT A SINGLE CONTROLLING FACTOR. AVAILABLE...DATA INDICATES THAT AN INTERRELATIONSHIP OF POROSITY, AVERAGE PORE VOLUME, AND PERMEABILITY CONTRIBUTES TO ELECTRODE FUEL CELL BEHAVIOR.

  11. Integrated fuel management system

    SciTech Connect

    Barbeau, D.E.

    1987-09-29

    An aircraft fuel management system to regulate fuel from an airframe reservoir is described. The system comprises: an aircraft turbine engine having a combustor providing propulsion for the aircraft; a fuel pump receiving fuel from the reservoir and supplying fuel to the turbine engine; a motor controlling the pump so as to provide fuel to the turbine engine; means for sensing at least one engine condition; means responsive to the sensing means for controlling fuel flow to the turbine engine, and wherein the pump and the motor are of the constant speed type and further comprising valve means for controlling the fuel flow rate to the turbine engine and wherein the controlling means modulates the position of the valve means.

  12. Alternative aircraft fuels technology

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1976-01-01

    NASA is studying the characteristics of future aircraft fuels produced from either petroleum or nonpetroleum sources such as oil shale or coal. These future hydrocarbon based fuels may have chemical and physical properties that are different from present aviation turbine fuels. This research is aimed at determining what those characteristics may be, how present aircraft and engine components and materials would be affected by fuel specification changes, and what changes in both aircraft and engine design would be required to utilize these future fuels without sacrificing performance, reliability, or safety. This fuels technology program was organized to include both in-house and contract research on the synthesis and characterization of fuels, component evaluations of combustors, turbines, and fuel systems, and, eventually, full-scale engine demonstrations. A review of the various elements of the program and significant results obtained so far are presented.

  13. Fuel quality combustion analysis

    NASA Technical Reports Server (NTRS)

    Naegeli, D. W.; Moses, C. A.

    1979-01-01

    A high pressure research combustor operating over a wide range of burner inlet conditions was used to determine the effects of fuel molecular structure on soot formation. Six test fuels with equal hydrogen content (12.8%) were blended to stress different molecular components and final boiling points. The fuels containing high concentrations (20%) of polycyclic aromatics and partially saturated polycyclic structures such as tetralin, produced more soot than would be expected from a hydrogen content correlation for typical petroleum based fuels. Fuels containing naphthenes such as decalin agreed with the hydrogen content correlation. The contribution of polycyclic aromatics to soot formation was equivalent to a reduction in fuel hydrogen content of about one percent. The fuel sensitivity to soot formation due to the polycyclic aromatic contribution decreased as burner inlet pressure and fuel/air ratio increased.

  14. Nuclear fuel element

    DOEpatents

    Zocher, Roy W.

    1991-01-01

    A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

  15. Reformulated diesel fuel

    DOEpatents

    McAdams, Hiramie T [Carrollton, IL; Crawford, Robert W [Tucson, AZ; Hadder, Gerald R [Oak Ridge, TN; McNutt, Barry D [Arlington, VA

    2006-03-28

    Reformulated diesel fuels for automotive diesel engines which meet the requirements of ASTM 975-02 and provide significantly reduced emissions of nitrogen oxides (NO.sub.x) and particulate matter (PM) relative to commercially available diesel fuels.

  16. Fuel collecting and recycling system

    SciTech Connect

    Cole, E.F.

    1980-06-10

    This system serves to collect and recycle fuel leftover in the fuel manifold and fuel distribution system of a gas turbine power plant when it is shutdown and operates in conjunction with the power plant's existing fuel control.

  17. COMPOSITE FUEL ELEMENT

    DOEpatents

    Hurford, W.J.; Gordon, R.B.; Johnson, W.A.

    1962-12-25

    A sandwich-type fuel element for a reactor is described. This fuel element has the shape of an elongated flat plate and includes a filler plate having a plurality of compartments therein in which the fuel material is located. The filler plate is clad on both sides with a thin cladding material which is secured to the filler plate only to completely enclose the fuel material in each compartment. (AEC)

  18. Direct hydrocarbon fuel cells

    DOEpatents

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  19. Navy Fuel Specification Standardization

    DTIC Science & Technology

    1992-04-01

    surfaced periodically to convert further to a single-fuel operation, i.e., one fuel for both aircraft and ship propulsion /power systems. This study...lead to the development of a single distillate fuel for ship propulsion , resulting eventually in the MIL-F-16884 Naval Distillate Fuel (NDF) used today...for both aircraft and ship propulsion /power systems. This report summarizes a study to consider this problem in light of current systems and

  20. Fakir fuel pump

    NASA Technical Reports Server (NTRS)

    1922-01-01

    In designing the Fakir fuel pump, the fundamental idea was to obtain a simple and reliable method of conveying the fuel from a low tank to the carburetor, with the avoidance of the faults of all former methods and the simultaneous warming of the fuel by means of the heat of compression generated. The principle of the Fakir fuel pump rests on the well-known principle of the diaphragm pump, which must be suitably adapted to the present purpose.

  1. Miniature ceramic fuel cell

    DOEpatents

    Lessing, Paul A.; Zuppero, Anthony C.

    1997-06-24

    A miniature power source assembly capable of providing portable electricity is provided. A preferred embodiment of the power source assembly employing a fuel tank, fuel pump and control, air pump, heat management system, power chamber, power conditioning and power storage. The power chamber utilizes a ceramic fuel cell to produce the electricity. Incoming hydro carbon fuel is automatically reformed within the power chamber. Electrochemical combustion of hydrogen then produces electricity.

  2. Transportation fuels from wood

    SciTech Connect

    Baker, E.G.; Elliott, D.C.; Stevens, D.J.

    1980-01-01

    The various methods of producing transportation fuels from wood are evaluated in this paper. These methods include direct liquefaction schemes such as hydrolysis/fermentation, pyrolysis, and thermochemical liquefaction. Indirect liquefaction techniques involve gasification followed by liquid fuels synthesis such as methanol synthesis or the Fischer-Tropsch synthesis. The cost of transportation fuels produced by the various methods are compared. In addition, three ongoing programs at Pacific Northwest Laboratory dealing with liquid fuels from wood are described.

  3. Jet fuel instability mechanisms

    NASA Technical Reports Server (NTRS)

    Daniel, S. R.

    1985-01-01

    The mechanisms of the formation of fuel-insoluble deposits were studied in several real fuels and in a model fuel consisting of tetralin in dodecane solution. The influence of addition to the fuels of small concentrations of various compounds on the quantities of deposits formed and on the formation and disappearance of oxygenated species in solution was assessed. The effect of temperature on deposit formation was also investigated over the range of 308-453 K.

  4. FUEL ROD ASSEMBLY

    DOEpatents

    Hutter, E.

    1959-09-01

    A cluster of nuclear fuel rods aod a tubular casing through which a coolant flows in heat-change contact with the ruel rods are described. The casting is of trefoil section and carries the fuel rods, each of which has two fin engaging the serrated fins of the other two fuel rods, whereby the fuel rods are held in the casing and are interlocked against relative longitudinal movement.

  5. Failsafe engine fuel control system

    SciTech Connect

    Martinsons, R.; Deutch, R.W.

    1987-11-03

    An engine fuel control system is described comprising: sensor means for providing separate more than two state electrical signals; fuel control means for receiving at least a primary control signal and providing a calculated engine fuel control signal as a function thereof; sensor signal conditioning circuit means coupled to the sensor means for receiving at least one of the electrical signals representative of sensed engine throttle position and sensed engine manifold pressure and providing; wherein the improvement comprises, failure detection means, for determining when the engine manifold pressure sensor signal is non-representative of actual engine manifold pressure and for providing a pressure sensor failure signal in response thereto. The sensor signal conditioning circuit means normally effectively provides a signal having magnitudes determined by at least the sensed manifold pressure signal to the fuel control means as the primary control signal in response to the absence of the pressure sensor failure signal. The system including an operator warning device which is activated in response to the pressure sensor failure signal indicating a failure of the pressure sensor.

  6. 40 CFR 205.160-6 - Passing or failing under SEA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Passing or failing under SEA. 205.160... ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.160-6 Passing or... the sample passes or fails (See applicable tables in Appendix II). If the number of failing...

  7. 40 CFR 1068.420 - How do I know when my engine family fails an SEA?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fails an SEA? 1068.420 Section 1068.420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL COMPLIANCE PROVISIONS FOR ENGINE PROGRAMS Selective Enforcement Auditing § 1068.420 How do I know when my engine family fails an SEA? (a) A failed engine or piece...

  8. 40 CFR 1068.420 - How do I know when my engine family fails an SEA?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... fails an SEA? 1068.420 Section 1068.420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... PROGRAMS Selective Enforcement Auditing § 1068.420 How do I know when my engine family fails an SEA? (a) A... for the SEA requirements when the number of failed engines/equipment is less than or equal to the...

  9. 40 CFR 1068.420 - How do I know when my engine family fails an SEA?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fails an SEA? 1068.420 Section 1068.420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... PROGRAMS Selective Enforcement Auditing § 1068.420 How do I know when my engine family fails an SEA? (a) A... for the SEA requirements when the number of failed engines/equipment is less than or equal to the...

  10. 43 CFR 30.222 - What happens if a party fails to comply with discovery?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false What happens if a party fails to comply with discovery? 30.222 Section 30.222 Public Lands: Interior Office of the Secretary of the Interior... Conference § 30.222 What happens if a party fails to comply with discovery? (a) If a party fails to...

  11. Solid oxide fuel cell matrix and modules

    DOEpatents

    Riley, B.

    1988-04-22

    Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs. 11 figs.

  12. Bulk characterization of (U, Pu) mixed carbide fuel for distribution of plutonium

    SciTech Connect

    Devi, K. V. Vrinda Khan, K. B.; Biju, K.; Kumar, Arun

    2015-06-24

    Homogeneous distribution of plutonium in (U, Pu) mixed fuels is important from fuel performance as well as reprocessing point of view. Radiation imaging and assay techniques are employed for the detection of Pu rich agglomerates in the fuel. A simulation study of radiation transport was carried out to analyse the technique of autoradiography so as to estimate the minimum detectability of Pu agglomerates in MC fuel with nominal PuC content of 70% using Monte Carlo simulations.

  13. Vented nuclear fuel element

    DOEpatents

    Grossman, Leonard N.; Kaznoff, Alexis I.

    1979-01-01

    A nuclear fuel cell for use in a thermionic nuclear reactor in which a small conduit extends from the outside surface of the emitter to the center of the fuel mass of the emitter body to permit escape of volatile and gaseous fission products collected in the center thereof by virtue of molecular migration of the gases to the hotter region of the fuel.

  14. Metallic fuel development

    SciTech Connect

    Walters, L.C.

    1987-01-01

    Metallic fuels are capable of achieving high burnup as a result of design modifications instituted in the late 1960's. The gap between the fuel slug and the cladding is fixed such that by the time the fuel swells to the cladding the fission gas bubbles interconnect and release the fission gas to an appropriately sized plenum volume. Interconnected porosity thus provides room for the fuel to deform from further swelling rather than stress the cladding. In addition, the interconnected porosity allows the fuel pin to be tolerant to transient events because as stresses are generated during a transient event the fuel flows rather than applying significant stress to the cladding. Until 1969 a number of metallic fuel alloys were under development in the US. At that time the metallic fuel development program in the US was discontinued in favor of ceramic fuels. However, development had proceeded to the point where it was clear that the zirconium addition to uranium-plutonium fuel would yield a ternary fuel with an adequately high solidus temperature and good compatibility with austenitic stainless steel cladding. Furthermore, several U-Pu-Zr fuel pins had achieved about 6 at.% bu by the late 1960's, without failure, and thus the prospect for high burnup was promising.

  15. Fuels from Recycling Systems

    ERIC Educational Resources Information Center

    Tillman, David A.

    1975-01-01

    Three systems, operating at sufficient scale, produce fuels that may be alternatives to oil and gas. These three recycling systems are: Black Clawson Fiberclaim, Franklin, Ohio; Union Carbide, South Charleston, West Virginia; and Union Electric, St. Louis, Missouri. These produce a wet fuel, a pyrolytic gas, and a dry fuel, respectively. (BT)

  16. Fireplaces and Fireplace Fuels.

    ERIC Educational Resources Information Center

    Metz, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fireplaces and fuels. Its objective is for the student to be able to discuss the structural design, operation, and efficiency of fireplaces and characteristics of different fireplace fuels. Some topics covered are fuels, elements…

  17. Alternative Fuels Data Center

    SciTech Connect

    2013-06-01

    Fact sheet describes the Alternative Fuels Data Center, which provides information, data, and tools to help fleets and other transportation decision makers find ways to reduce petroleum consumption through the use of alternative and renewable fuels, advanced vehicles, and other fuel-saving measures.

  18. Fuel cell generator

    DOEpatents

    Isenberg, Arnold O.

    1983-01-01

    High temperature solid oxide electrolyte fuel cell generators which allow controlled leakage among plural chambers in a sealed housing. Depleted oxidant and fuel are directly reacted in one chamber to combust remaining fuel and preheat incoming reactants. The cells are preferably electrically arranged in a series-parallel configuration.

  19. Vehicle fuel system

    DOEpatents

    Risse, John T.; Taggart, James C.

    1976-01-01

    A vehicle fuel system comprising a plurality of tanks, each tank having a feed and a return conduit extending into a lower portion thereof, the several feed conduits joined to form one supply conduit feeding fuel to a supply pump and using means, unused fuel being returned via a return conduit which branches off to the several return conduits.

  20. Optoacoustic Spectroscopy to Detect Hydrazine Fuels.

    DTIC Science & Technology

    1981-07-01

    the use of optoacoustic spectroscopy to obtain spectra for inorganic samiples and biological materials (304-312). Parker (258) and Parker and Hitke...Appi Spectroscopy 34:/6 (19801). 196. Lutt , K. F. A new recording method for gas analysis by mneans of infrared ibsorption without spectral splitting...Photoacoustic spectroscopy of biological materials. Science 181:657 (1973). 306. Rosencwaig, A. Photoacoustic spectroscopy of solids. Optics Commun 7:305

  1. FGF23 fails to inhibit uremic parathyroid glands.

    PubMed

    Canalejo, Rocío; Canalejo, Antonio; Martinez-Moreno, Julio Manuel; Rodriguez-Ortiz, M Encarnacion; Estepa, Jose C; Mendoza, Francisco Javier; Munoz-Castaneda, Juan Rafael; Shalhoub, Victoria; Almaden, Yolanda; Rodriguez, Mariano

    2010-07-01

    Fibroblast growth factor 23 (FGF23) modulates mineral metabolism by promoting phosphaturia and decreasing the production of 1,25-dihydroxyvitamin D(3). FGF23 decreases parathyroid hormone (PTH) mRNA and secretion, but despite a marked elevation in FGF23 in uremia, PTH production increases. Here, we investigated the effect of FGF23 on parathyroid function in normal and uremic hyperplastic parathyroid glands in rats. In normal parathyroid glands, FGF23 decreased PTH production, increased expression of both the parathyroid calcium-sensing receptor and the vitamin D receptor, and reduced cell proliferation. Furthermore, FGF23 induced phosphorylation of extracellular signal-regulated kinase 1/2, which mediates the action of FGF23. In contrast, in hyperplastic parathyroid glands, FGF23 did not reduce PTH production, did not affect expression of the calcium-sensing receptor or vitamin D receptor, and did not affect cell proliferation. In addition, FGF23 failed to activate the extracellular signal-regulated kinase 1/2-mitogen-activated protein kinase pathway in hyperplastic parathyroid glands. We observed very low expression of the FGF23 receptor 1 and the co-receptor Klotho in uremic hyperplastic parathyroid glands, which may explain the lack of response to FGF23 in this tissue. In conclusion, in hyperparathyroidism secondary to renal failure, the parathyroid cells resist the inhibitory effects of FGF23, perhaps as a result of the low expression of FGF23 receptor 1 and Klotho in this condition.

  2. What to do if an initial antidepressant fails?

    PubMed Central

    McIntyre, Roger S.; Müller, Aleksandra; Mancini, Deborah A.; Silver, Eric S.

    2003-01-01

    OBJECTIVE: To provide family physicians with practical ways of managing depressed patients responding insufficiently to initial antidepressant treatment. QUALITY OF EVIDENCE: A search of MEDLINE and relevant bibliographies showed most studies could be categorized as level III evidence. Few well controlled studies (eg, level I evidence) specify treatment of next choice in rigorously defined treatment-refractory depression (TRD). MAIN MESSAGE: Failure to achieve and sustain full symptom remission affects relatively few treated depressed patients. Most chronically depressed people are not absolutely resistant but are relatively resistant to treatment; they fail to achieve the goals of treatment because of improper diagnosis or insufficient treatment application. The literature on TRD has largely focused on medication strategies; fewer studies investigated psychosocial approaches. The best established augmentation strategies are lithium salts and triidothyronine (T3). Combination antidepressants have become clinical psychiatrists' preferred treatment, despite limited evidence. Electroconvulsive therapy (ECT) remains a feasible option for TRD, but response rates are poor among people with TRD. High relapse rates after ECT remain a serious and common clinical dilemma. CONCLUSION: Family physicians should familiarize themselves with some new strategies to modify inadequate response to initial antidepressant treatment. PMID:12729241

  3. Outcome of neurolysis for failed tarsal tunnel surgery.

    PubMed

    Barker, Allison R; Rosson, Gedge D; Dellon, A Lee

    2008-02-01

    Revision tarsal tunnel surgery was performed on 44 patients (two bilaterally). The surgical procedure included a neurolysis of the tibial nerve in the tarsal tunnel, the medial plantar, lateral plantar, and calcaneal nerves in their respective tunnels, excision of the intertunnel septum, and neuroma resection as indicated. A painful tarsal tunnel scar or painful heel was treated, respectively, by resection of the distal saphenous nerve or a calcaneal nerve branch. Postoperative, immediate ambulation was permitted. Outcomes were assessed with a numerical grading scale that included neurosensory measurements. Outcomes were also assessed by patient satisfaction and their own estimate of residual pain and/or numbness. Mean follow-up time was 2.2 years. Outcomes in terms of patient satisfaction were 54% excellent, 24% good, 13% fair, and 9% poor results. The mean preoperative numerical score was 6.0 and the mean postoperative score was 2.7. There was a significant improvement seen, based on the median difference between scores (P<0.001). Prognostic indicators of poor results in our patient group were coexisting lumbosacral disc disease and/or neuropathy. An approach related to resecting painful cutaneous nerves and neurolysis of all tibial nerve branches at the ankle offers hope for relief of pain and recovery of sensation for the majority of patients with failed previous tarsal tunnel surgery.

  4. Failed back surgery syndrome: review and new hypotheses

    PubMed Central

    Bordoni, Bruno; Marelli, Fabiola

    2016-01-01

    Failed back surgery syndrome (FBSS) is a term used to define an unsatisfactory outcome of a patient who underwent spinal surgery, irrespective of type or intervention area, with persistent pain in the lumbosacral region with or without it radiating to the leg. The possible reasons and risk factors that would lead to FBSS can be found in distinct phases: in problems already present in the patient before a surgical approach, such as spinal instability, during surgery (for example, from a mistake by the surgeon), or in the postintervention phase in relation to infections or biomechanical alterations. This article reviews the current literature on FBSS and tries to give a new hypothesis to understand the reasons for this clinical problem. The dysfunction of the diaphragm muscle is a component that is not taken into account when trying to understand the reasons for this syndrome, as there is no existing literature on the subject. The diaphragm is involved in chronic lower back and sacroiliac pain and plays an important role in the management of pain perception. PMID:26834497

  5. Experimenting `learn by doing' and `learn by failing'

    NASA Astrophysics Data System (ADS)

    Pozzi, Rossella; Noè, Carlo; Rossi, Tommaso

    2015-01-01

    According to the literature, in recent years, developing experiential learning has fulfilled the requirement of a deep understanding of lean philosophy by engineering students, demonstrating the advantages and disadvantages of some of the key principles of lean manufacturing. On the other hand, the literature evidences how some kinds of game-based experiential learning overlook daily difficulties, which play a central role in manufacturing systems. To fill the need of a game overcoming such lack of vision, an innovative game direct in-field, named Kart Factory, has been developed. Actual production shifts are simulated, while keeping all the elements peculiar to a real production set (i.e. complexity, effort, safety). The working environment is a real pedal car assembly department, the products to be assembled have relevant size and weight (i.e. up to 35 kg approximately), and the provided tools are real production equipment (e.g. keys, screwdrivers, trans-pallets, etc.). Due to the need to maximise the impact on students, a labour-intensive process characterises the production department. The whole training process is based on three educational principles: Experience Value Principle, Error Value Principle, and Team Value Principle. As the 'learn by doing' and 'learn by failing' are favoured, the theory follows the practice, while crating the willingness to 'do' instead of just designing or planning. The gathered data prove the Kart Factory's effectiveness in reaching a good knowledge of lean concepts, notwithstanding the students' initial knowledge level.

  6. Product life trade-offs: what if products fail early?

    PubMed

    Skelton, Alexandra C H; Allwood, Julian M

    2013-02-05

    Increasing product life allows the embodied emissions in products to be spread across a longer period but can mean that opportunities to improve use-phase efficiency are foregone. In this paper, a model that evaluates this trade-off is presented and used to estimate the optimal product life for a range of metal-intensive products. Two strategies that have potential to save emissions are explored: (1) adding extra embodied emissions to make products more sturdy, increasing product life, and (2) increasing frequency of use, causing early product failure to take advantage of improvements in use-phase efficiency. These strategies are evaluated for two specific case studies (long-life washing machines and more frequent use of vehicles through car clubs) and for a range of embodied and use-phase intensive products under different use-phase improvement rate assumptions. Particular emphasis is placed on the fact that products often fail neither at their design life nor at their optimal life. Policy recommendations are then made regarding the targeting of these strategies according to product characteristics and the timing of typical product failure relative to optimal product life.

  7. Social mind representation: where does it fail in frontotemporal dementia?

    PubMed

    Ruby, Perrine; Schmidt, Christina; Hogge, Michaël; D'Argembeau, Arnaud; Collette, Fabienne; Salmon, Eric

    2007-04-01

    We aimed at investigating social disability and its cerebral correlates in frontotemporal dementia (FTD). To do so, we contrasted answers of patients with early-stage FTD and of their relatives on personality trait judgment and on behavior prediction in social and emotional situations. Such contrasts were compared to control contrasts calculated with answers of matched controls tested with their relatives. In addition, brain metabolism was measured in patients with positron emission tomography and the [(18)F]fluorodeoxyglucose method. Patients turned out to be as accurate as controls in describing their relative's personality, but they failed to predict their relative's behavior in social and emotional circumstances. Concerning the self, patients were impaired both in current personality assessment and in prediction of their own behavior. Those two self-evaluation measures did not correlate. Only patients' anosognosia for social behavioral disability was found to be related to decreased metabolic activity in the left temporal pole. Such results suggest that anosognosia for social disability in FTD originates in impaired processing of emotional autobiographical information, leading to a self-representation that does not match current behavior. Moreover, we propose that perspective-taking disability participates in anosognosia, preventing patients from correcting their inaccurate self-representation based on their relative's perspective.

  8. Organism-level models: When mechanisms and statistics fail us

    NASA Astrophysics Data System (ADS)

    Phillips, M. H.; Meyer, J.; Smith, W. P.; Rockhill, J. K.

    2014-03-01

    Purpose: To describe the unique characteristics of models that represent the entire course of radiation therapy at the organism level and to highlight the uses to which such models can be put. Methods: At the level of an organism, traditional model-building runs into severe difficulties. We do not have sufficient knowledge to devise a complete biochemistry-based model. Statistical model-building fails due to the vast number of variables and the inability to control many of them in any meaningful way. Finally, building surrogate models, such as animal-based models, can result in excluding some of the most critical variables. Bayesian probabilistic models (Bayesian networks) provide a useful alternative that have the advantages of being mathematically rigorous, incorporating the knowledge that we do have, and being practical. Results: Bayesian networks representing radiation therapy pathways for prostate cancer and head & neck cancer were used to highlight the important aspects of such models and some techniques of model-building. A more specific model representing the treatment of occult lymph nodes in head & neck cancer were provided as an example of how such a model can inform clinical decisions. A model of the possible role of PET imaging in brain cancer was used to illustrate the means by which clinical trials can be modelled in order to come up with a trial design that will have meaningful outcomes. Conclusions: Probabilistic models are currently the most useful approach to representing the entire therapy outcome process.

  9. BLACK HOLE FORMATION IN FAILING CORE-COLLAPSE SUPERNOVAE

    SciTech Connect

    O'Connor, Evan; Ott, Christian D. E-mail: cott@tapir.caltech.edu

    2011-04-01

    We present results of a systematic study of failing core-collapse supernovae and the formation of stellar-mass black holes (BHs). Using our open-source general-relativistic 1.5D code GR1D equipped with a three-species neutrino leakage/heating scheme and over 100 presupernova models, we study the effects of the choice of nuclear equation of state (EOS), zero-age main sequence (ZAMS) mass and metallicity, rotation, and mass-loss prescription on BH formation. We find that the outcome, for a given EOS, can be estimated, to first order, by a single parameter, the compactness of the stellar core at bounce. By comparing protoneutron star (PNS) structure at the onset of gravitational instability with solutions of the Tolman-Oppenheimer-Volkof equations, we find that thermal pressure support in the outer PNS core is responsible for raising the maximum PNS mass by up to 25% above the cold NS value. By artificially increasing neutrino heating, we find the critical neutrino heating efficiency required for exploding a given progenitor structure and connect these findings with ZAMS conditions, establishing, albeit approximately, for the first time based on actual collapse simulations, the mapping between ZAMS parameters and the outcome of core collapse. We also study the effect of progenitor rotation and find that the dimensionless spin of nascent BHs may be robustly limited below a* = Jc/GM{sup 2} = 1 by the appearance of nonaxisymmetric rotational instabilities.

  10. Ouachita trough: Part of a Cambrian failed rift system

    NASA Astrophysics Data System (ADS)

    Lowe, Donald R.

    1985-11-01

    Pre-flysch (Cambrian-Mississippian) strata of the Ouachita Mountains of Arkansas and Oklahoma include two main sandstone lithofacies: (1) a craton-derived lithofacies made up largely of mature medium- to coarse-grained quartzose and carbonate detritus and, in some units, sediment eroded from exposed basement rocks and (2) an orogen-derived facies made up mainly of fine-grained quartzose sedimentary and metasedimentary debris and possibly, in lower units, a volcaniclastic component. Paleocurrent and distribution patterns indicate that detritus of facies I in the Benton uplift was derived from north and detritus of facies II throughout the Ouachitas was derived from south and east of the depositional basin. Overall sedimentological results suggest that the Ouachita trough was a relatively narrow, two-sided basin throughout most and probably all of its existence and never formed the southern margin of the North American craton. Regional comparisons suggest that it was one of several basins, including the Southern Oklahoma aulacogen, Reelfoot Rift, Illinois Basin, and Rome trough, that formed as a Cambrian failed rift system 150 to 250 m.y. after initial rifting along the Appalachian margin of the North American craton.

  11. Fluvoxamine, a new antidepressant drug, fails to show antiserotonin activity.

    PubMed

    Maj, J; Rogóz, Z; Skuza, G

    1982-07-09

    Fluvoxamine, (E)-5-methoxy-4'-(trifluoromethyl)valerophenone O-2(2-aminoethyl)oxime, a new antidepressant drug inhibiting serotonin (5-HT) uptake, was studied in rats and mice in order to check whether it has any central anti-5-HT activity, as do some tricyclic antidepressants, e.g. amitriptyline and doxepin. Fluvoxamine did not influence either the 5-hydroxytryptophan-induced head twitch response in mice or the tryptamine convulsions in rats. In the hind limb flexor reflex of the spinal rat the stimulation induced by fenfluramine was inhibited, that induced by LSD was not changed. Fluvoxamine also antagonized the hyperthermia (at ambient temperature of 28 degrees C), induced in rats by fenfluramine or p-chloroamphetamine. The hyperthermia caused by m-chlorophenylpiperazine was not inhibited. Fluvoxamine did not antagonize the 5-HT pressor effect in pithed rats. It has no effect on the immobility time in the behavioural despair test in rats. The results indicate that fluvoxamine fails to show anti-5-HT activity.

  12. Cluster Development Test 2: An Assessment of a Failed Test

    NASA Technical Reports Server (NTRS)

    Machin, Ricardo A.; Evans, Carol T.

    2009-01-01

    On 31 July 2008 the National Aeronautics and Space Administration Crew Exploration Vehicle Parachute Assembly System team conducted the final planned cluster test of the first generation parachute recovery system design. The two primary test objectives were to demonstrate the operation of the complete parachute system deployed from a full scale capsule simulator and to demonstrate the test technique of separating the capsule simulator from the Low Velocity Air Drop pallet used to extract the test article from a United States Air Force C-17 aircraft. The capsule simulator was the Parachute Test Vehicle with an accurate heat shield outer mold line and forward bay compartment of the Crew Exploration Vehicle Command Module. The Parachute Test Vehicle separated cleanly from the pallet following extraction, but failed to reach test conditions resulting in the failure of the test and the loss of the test assets. No personnel were injured. This paper will discuss the design of the test and the findings of the team that investigated the test, including a discussion of what were determined to be the root causes of the failure.

  13. Requirements: Towards an understanding on why software projects fail

    NASA Astrophysics Data System (ADS)

    Hussain, Azham; Mkpojiogu, Emmanuel O. C.

    2016-08-01

    Requirement engineering is at the foundation of every successful software project. There are many reasons for software project failures; however, poorly engineered requirements process contributes immensely to the reason why software projects fail. Software project failure is usually costly and risky and could also be life threatening. Projects that undermine requirements engineering suffer or are likely to suffer from failures, challenges and other attending risks. The cost of project failures and overruns when estimated is very huge. Furthermore, software project failures or overruns pose a challenge in today's competitive market environment. It affects the company's image, goodwill, and revenue drive and decreases the perceived satisfaction of customers and clients. In this paper, requirements engineering was discussed. Its role in software projects success was elaborated. The place of software requirements process in relation to software project failure was explored and examined. Also, project success and failure factors were also discussed with emphasis placed on requirements factors as they play a major role in software projects' challenges, successes and failures. The paper relied on secondary data and empirical statistics to explore and examine factors responsible for the successes, challenges and failures of software projects in large, medium and small scaled software companies.

  14. Ranking nodes in growing networks: When PageRank fails

    PubMed Central

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-01-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes. PMID:26553630

  15. Why have we failed to cure Alzheimer's disease?

    PubMed

    Korczyn, Amos D

    2012-01-01

    There is widespread recognition in the urgency to understand the causes and mechanisms of senile dementia. Attempts to find cures for Alzheimer's disease (AD) have, however, failed so far, in spite of enormous investments, intellectual and financial. We therefore have to reconsider the problem from new angles. AD is regarded as a disease because of its clinical manifestations and underlying pathology. However, this combination does not define a disease but rather a syndrome, just like hepatic cirrhosis in which liver pathology causes metabolic changes, but which can result from many different etiologies. It is unlikely that attacking a downstream phenomenon, like apoptosis or amyloid-β accumulation, can cure AD, or prevent the progression of the disease. It is probable that senile dementia is the result of a combination of several processes, working differently in each person. Epidemiological studies have identified many risk factors for "senile dementia of the Alzheimer type", some genetic but most environmental and therefore modifiable. Thus, a concerted action to fight the dementia epidemic must be made by aggressive action against its risk factors, and this battle must begin in midlife, not in old age.

  16. Why does informed consent fail? A discourse analytic approach.

    PubMed

    Ness, David E; Kiesling, Scott F; Lidz, Charles W

    2009-01-01

    Informed consent often fails to meet the intended goals that a prospective subject should understand fully and choose autonomously to participate in research. The current study is an attempt to understand such failures by applying linguistic methods of discourse analysis to the transcripts of informed consent interviews. Elements of conversation and of the frame of discourse were analyzed to understand how the participants shaped their spoken interaction during the interview. We looked at the degree to which the subject appeared to be fully informed, at the problem of therapeutic misconception, and at the degree to which the subject was helped to explore concerns relevant to the choice at hand. We found that lapses or miscommunications could be understood specifically in terms of conversational elements and framing. This kind of detailed, language-based analysis is an alternative to approaches that are more abstract and inferential, such as those that are based upon the attitudes or the cognitive performance of speakers. We discuss possible educational and research implications of this approach.

  17. Over the Pole: A Fuel Efficiency Analysis of Employing Joint Base Elmendorf-Richardson for Polar Route Utilization

    DTIC Science & Technology

    2014-06-13

    hinder operations  Reduction in fuel usage will lower operational costs  Polar route considerations such as volcanic activity and fuel freezing...there are certain factors that can limit its use such as volcanic activity, unstable solar activity, solar radiation and fuel freezing potential...other major factor that prevents more extensive usage of polar routing is that the Kyrgyz government failed to renew the US lease of the Manas

  18. Neutronic fuel element fabrication

    DOEpatents

    Korton, George

    2004-02-24

    This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure

  19. Successful placement of the Essure device after a failed procedure using the Adiana system for hysteroscopic sterilisation

    PubMed Central

    Schuurman, Teska; Veersema, Sebastiaan

    2011-01-01

    This case report describes a successful hysteroscopic sterilisation using the Essure Permanent Birth Control device (Conceptus Inc., Mountain View, California, United States) after a failed procedure of the Adiana Permanent Contraception system (Hologic, Inc., Bedford, Maryland, United States). The delivery catheter of the Adiana system was able to be inserted into the left fallopian tube without difficulty and per manufacturer specifications. However, the position detection array was unable to sense four-quadrant tissue contact. The same issue occurred at the contralateral tube. Using the Essure system, the coils were able to be placed in both ostia easily and adequately. In patients in whom the Adiana system fails to occlude the fallopian tubes due to procedural, anatomic or device-related factors, the Essure procedure may be an efficient alternative. PMID:22689274

  20. Assessment of reactivity transient experiments with high burnup fuel

    SciTech Connect

    Ozer, O.; Yang, R.L.; Rashid, Y.R.; Montgomery, R.O.

    1996-03-01

    A few recent experiments aimed at determining the response of high-burnup LWR fuel during a reactivity initiated accident (RIA) have raised concerns that existing failure criteria may be inappropriate for such fuel. In particular, three experiments (SPERT CDC-859, NSRR HBO-1 and CABRI REP Na-1) appear to have resulted in fuel failures at only a fraction of the anticipated enthalpy levels. In evaluating the results of such RIA simulation experiments, however, it is necessary that the following two key considerations be taken into account: (1) Are the experiments representative of conditions that LWR fuel would experience during an in-reactor RIA event? (2) Is the fuel that is being utilized in the tests representative of the present (or anticipated) population of LWR fuel? Conducting experiments under conditions that can not occur in-reactor can trigger response modes that could not take place during in-reactor operation. Similarly, using unrepresentative fuel samples for the tests will produce failure information that is of limited relevance to commercial LWR fuel. This is particularly important for high-burnup fuel since the manner under which the test samples are base-irradiated prior to the test will impact the mechanical properties of the cladding and will therefore affect the RIA response. A good example of this effect can be seen in the results of the SPERT CDC-859 test and in the NSRR JM-4 and JM-5 tests. The conditions under which the fuel used for these tests was fabricated and/or base-irradiated prior to the RIA pulse resulted in the formation of multiple cladding defects in the form of hydride blisters. When this fuel was subjected to the RIA power pulse, it failed by developing multiple cracks that were closely correlated with the locations of the pre-existing hydride blisters. In the case of the JM tests, many of the cracks formed within the blisters themselves and did not propagate beyond the heavily hydrided regions.

  1. Laser-Based Characterization of Nuclear Fuel Plates

    SciTech Connect

    James A. Smith; David L. Cottle; Barry H. Rabin

    2013-07-01

    Ensuring the integrity of fuel-clad and clad-clad bonding in nuclear fuels is important for safe reactor operation and assessment of fuel performance, yet the measurement of bond strengths in actual fuels has proved challenging. The laser shockwave technique (LST) originally developed to characterize structural adhesion in composites is being employed to characterize interface strength in a new type of plate fuel being developed at Idaho National Laboratory (INL). LST is a non-contact method that uses lasers for the generation and detection of large-amplitude acoustic waves and is well suited for application to both fresh and irradiated nuclear-fuel plates. This paper will report on initial characterization results obtained from fresh fuel plates manufactured by different processes, including hot isostatic pressing, friction stir welding, and hot rolling.

  2. Laser-based characterization of nuclear fuel plates

    SciTech Connect

    Smith, James A.; Cottle, Dave L.; Rabin, Barry H.

    2014-02-18

    Ensuring the integrity of fuel-clad and clad-clad bonding in nuclear fuels is important for safe reactor operation and assessment of fuel performance, yet the measurement of bond strengths in actual fuels has proved challenging. The laser shockwave technique (LST) originally developed to characterize structural adhesion in composites is being employed to characterize interface strength in a new type of plate fuel being developed at Idaho National Laboratory (INL). LST is a non-contact method that uses lasers for the generation and detection of large-amplitude acoustic waves and is well suited for application to both fresh and irradiated nuclear-fuel plates. This paper will report on initial characterization results obtained from fresh fuel plates manufactured by different processes, including hot isostatic pressing, friction stir welding, and hot rolling.

  3. Fuel characteristics pertinent to the design of aircraft fuel systems

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, R R

    1953-01-01

    Because of the importance of fuel properties in design of aircraft fuel systems the present report has been prepared to provide information on the characteristics of current jet fuels. In addition to information on fuel properties, discussions are presented on fuel specifications, the variations among fuels supplied under a given specification, fuel composition, and the pertinence of fuel composition and physical properties to fuel system design. In some instances the influence of variables such as pressure and temperature on physical properties is indicated. References are cited to provide fuel system designers with sources of information containing more detail than is practicable in the present report.

  4. Fuel Cell Handbook update

    SciTech Connect

    Owens, W.R.; Hirschenhofer, J.H.; Engleman, R.R. Jr.; Stauffer, D.B.

    1993-11-01

    The objective of this work was to update the 1988 version of DOE`s Fuel Cell Handbook. Significant developments in the various fuel cell technologies required revisions to reflect state-of-the-art configurations and performance. The theoretical presentation was refined in order to make the handbook more useful to both the casual reader and fuel cell or systems analyst. In order to further emphasize the practical application of fuel cell technologies, the system integration information was expanded. In addition, practical elements, such as suggestions and guidelines to approximate fuel cell performance, were provided.

  5. Alternative aircraft fuels

    NASA Technical Reports Server (NTRS)

    Longwell, J. P.; Grobman, J. S.

    1977-01-01

    The efficient utilization of fossil fuels by future jet aircraft may necessitate the broadening of current aviation turbine fuel specifications. The most significant changes in specifications would be an increased aromatics content and a higher final boiling point in order to minimize refinery energy consumption and costs. These changes would increase the freezing point and might lower the thermal stability of the fuel, and could cause increased pollutant emissions, increased combustor liner temperatures, and poorer ignition characteristics. The effects that broadened specification fuels may have on present-day jet aircraft and engine components and the technology required to use fuels with broadened specifications are discussed.

  6. Alternative aviation turbine fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1977-01-01

    The efficient utilization of fossil fuels by future jet aircraft may necessitate the broadening of current aviation turbine fuel specifications. The most significant changes in specifications would be an increased aromatics content and a higher final boiling point in order to minimize refinery energy consumption and costs. These changes would increase the freezing point and might lower the thermal stability of the fuel and could cause increased pollutant emissions, increased smoke and carbon formation, increased combustor liner temperatures, and poorer ignition characteristics. This paper discusses the effects that broadened specification fuels may have on present-day jet aircraft and engine components and the technology required to use fuels with broadened specifications.

  7. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    PubMed

    Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

  8. Fuel nozzle assembly

    DOEpatents

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Lacey, Benjamin Paul; York, William David; Stevenson, Christian Xavier

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  9. NUCLEAR REACTOR FUEL ELEMENT

    DOEpatents

    Wheelock, C.W.; Baumeister, E.B.

    1961-09-01

    A reactor fuel element utilizing fissionable fuel materials in plate form is described. This fuel element consists of bundles of fuel-bearing plates. The bundles are stacked inside of a tube which forms the shell of the fuel element. The plates each have longitudinal fins running parallel to the direction of coolant flow, and interspersed among and parallel to the fins are ribs which position the plates relative to each other and to the fuel element shell. The plate bundles are held together by thin bands or wires. The ex tended surface increases the heat transfer capabilities of a fuel element by a factor of 3 or more over those of a simple flat plate.

  10. The pyrazinamide susceptibility breakpoint above which combination therapy fails

    PubMed Central

    Gumbo, Tawanda; Chigutsa, Emmanuel; Pasipanodya, Jotam; Visser, Marianne; van Helden, Paul D.; Sirgel, Frederick A; McIlleron, Helen

    2014-01-01

    Objectives To identify the pyrazinamide MIC above which standard combination therapy fails. Methods MICs of pyrazinamide were determined for Mycobacterium tuberculosis isolates, cultured from 58 patients in a previous randomized clinical trial in Cape Town, South Africa. The MICs were determined using BACTEC MGIT 960 for isolates that were collected before standard treatment with isoniazid, rifampicin, pyrazinamide and ethambutol commenced. Weekly sputum collections were subsequently made for 8 weeks in order to culture M. tuberculosis in Middlebrook broth medium. Classification and regression tree (CART) analysis was utilized to identify the pyrazinamide MIC predictive of sputum culture results at the end of pyrazinamide therapy. The machine learning-derived susceptibility breakpoints were then confirmed using standard association statistics that took into account confounders of 2 month sputum conversion. Results The pyrazinamide MIC range was 12.5 to >100 mg/L for the isolates prior to therapy. The epidemiological 95% cut-off value was >100 mg/L. The 2 month sputum conversion rate in liquid cultures was 26% by stringent criteria and 48% by less stringent criteria. CART analysis identified an MIC breakpoint of 50 mg/L, above which patients had poor sputum conversion rates. The relative risk of poor sputum conversion was 1.5 (95% CI: 1.2–1.8) for an MIC >50 mg/L compared with an MIC ≤50 mg/L. Conclusions We propose a pyrazinamide susceptibility breakpoint of 50 mg/L for clinical decision making and for development of rapid susceptibility assays. This breakpoint is identical to that identified using computer-aided simulations of hollow fibre system output. PMID:24821594

  11. Autism: are mental health services failing children and parents?

    PubMed

    Read, Nicola; Schofield, Adél

    2010-01-01

    Autism is not a menta illness but a neurodevelopmental disorder. However, the prevalence of mental health problems such as depression among children and young people with autism is high. One in 10 children and young people who use Child and Adolescent Mental Health Services (CAMHS) has autism. Recent research by The National Autistic Society (NAS) into the effectiveness of these services has revealed a serious lack of understanding and support, with some families reporting that they have had to wait for years to receive help. The research involved a survey of 455 parents of children and young people with autism, together with qualitative findings from parental and young people's focus groups, a survey of CAMHS professionals and visits to CAMHS sites. Responses from parents, young people and professionals indicated that CAMHS did not have the knowledge or the skills to identify or treat mental health problems in children with autism.This can have profound consequences for the health and well-being of the whole family. Autism is a complex disability that can make it harder to diagnose concomitant mental health problems. It is a condition that can make it more difficult for professionals to develop successful, trusting relationships with children, and requires services to be adapted to the individual child. Mainstream interventions and treatments, if unadjusted, will usually fail to improve the mental health of a child with autism and may even make things worse.This article explores how CAMHS services might better meet the needs of children with autism and their families, including improvements in the transition to adult mental health services. In June 2010 NAS launched You Need to Know, a campaign calling on the Government to give priority to improving CAMHS services for children with autism and to support loca areas in delivering the changes that families and front-line professionals are calling for.

  12. Machine-learning-assisted materials discovery using failed experiments

    NASA Astrophysics Data System (ADS)

    Raccuglia, Paul; Elbert, Katherine C.; Adler, Philip D. F.; Falk, Casey; Wenny, Malia B.; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A.; Schrier, Joshua; Norquist, Alexander J.

    2016-05-01

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on ‘dark’ reactions—failed or unsuccessful hydrothermal syntheses—collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted

  13. Heart failure: when form fails to follow function.

    PubMed

    Katz, Arnold M; Rolett, Ellis L

    2016-02-01

    Cardiac performance is normally determined by architectural, cellular, and molecular structures that determine the heart's form, and by physiological and biochemical mechanisms that regulate the function of these structures. Impaired adaptation of form to function in failing hearts contributes to two syndromes initially called systolic heart failure (SHF) and diastolic heart failure (DHF). In SHF, characterized by high end-diastolic volume (EDV), the left ventricle (LV) cannot eject a normal stroke volume (SV); in DHF, with normal or low EDV, the LV cannot accept a normal venous return. These syndromes are now generally defined in terms of ejection fraction (EF): SHF became 'heart failure with reduced ejection fraction' (HFrEF) while DHF became 'heart failure with normal or preserved ejection fraction' (HFnEF or HFpEF). However, EF is a chimeric index because it is the ratio between SV--which measures function, and EDV--which measures form. In SHF the LV dilates when sarcomere addition in series increases cardiac myocyte length, whereas sarcomere addition in parallel can cause concentric hypertrophy in DHF by increasing myocyte thickness. Although dilatation in SHF allows the LV to accept a greater venous return, it increases the energy cost of ejection and initiates a vicious cycle that contributes to progressive dilatation. In contrast, concentric hypertrophy in DHF facilitates ejection but impairs filling and can cause heart muscle to deteriorate. Differences in the molecular signals that initiate dilatation and concentric hypertrophy can explain why many drugs that improve prognosis in SHF have little if any benefit in DHF.

  14. Machine-learning-assisted materials discovery using failed experiments.

    PubMed

    Raccuglia, Paul; Elbert, Katherine C; Adler, Philip D F; Falk, Casey; Wenny, Malia B; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A; Schrier, Joshua; Norquist, Alexander J

    2016-05-05

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on 'dark' reactions--failed or unsuccessful hydrothermal syntheses--collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted conditions

  15. Metabolomic Profiling in Individuals with a Failing Kidney Allograft

    PubMed Central

    Biancone, Luigi; Bussolino, Stefania; Merugumala, Sai; Tezza, Sara; D’Addio, Francesca; Ben Nasr, Moufida; Valderrama-Vasquez, Alessandro; Usuelli, Vera; De Zan, Valentina; El Essawy, Basset; Venturini, Massimo; Secchi, Antonio; De Cobelli, Francesco; Lin, Alexander; Chandraker, Anil; Fiorina, Paolo

    2017-01-01

    Background Alteration of certain metabolites may play a role in the pathophysiology of renal allograft disease. Methods To explore metabolomic abnormalities in individuals with a failing kidney allograft, we analyzed by liquid chromatography-mass spectrometry (LC-MS/MS; for ex vivo profiling of serum and urine) and two dimensional correlated spectroscopy (2D COSY; for in vivo study of the kidney graft) 40 subjects with varying degrees of chronic allograft dysfunction stratified by tertiles of glomerular filtration rate (GFR; T1, T2, T3). Ten healthy non-allograft individuals were chosen as controls. Results LC-MS/MS analysis revealed a dose-response association between GFR and serum concentration of tryptophan, glutamine, dimethylarginine isomers (asymmetric [A]DMA and symmetric [S]DMA) and short-chain acylcarnitines (C4 and C12), (test for trend: T1-T3 = p<0.05; p = 0.01; p<0.001; p = 0.01; p = 0.01; p<0.05, respectively). The same association was found between GFR and urinary levels of histidine, DOPA, dopamine, carnosine, SDMA and ADMA (test for trend: T1-T3 = p<0.05; p<0.01; p = 0.001; p<0.05; p = 0.001; p<0.001; p<0.01, respectively). In vivo 2D COSY of the kidney allograft revealed significant reduction in the parenchymal content of choline, creatine, taurine and threonine (all: p<0.05) in individuals with lower GFR levels. Conclusions We report an association between renal function and altered metabolomic profile in renal transplant individuals with different degrees of kidney graft function. PMID:28052095

  16. Management of Failing Prosthetic Bypass Grafts with Metallic Stent Placement

    SciTech Connect

    Siskin, Gary P.; Stainken, Brian F.; Mandell, Valerie S.; Darling, R. Clement; Dowling, Kyran; Herr, Allen

    1999-09-15

    Purpose: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. Methods: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n= 3), rest pain (n= 9), and minor or major tissue loss (n= 3). Lesions were at the proximal anastomosis (n= 6), the distal anastomosis (n= 3), or within the graft (n= 6). Results: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. Conclusion: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.

  17. Measuring mental disorders: The failed commensuration project of DSM-5.

    PubMed

    Whooley, Owen

    2016-10-01

    Commensuration - the comparison of entities according to a common quantitative metric - is a key process in efforts to rationalize medicine. The push toward evidence-based medicine and quantitative assessment has led to the proliferation of metrics in healthcare. While social scientific attention has revealed the effects of these metrics once institutionalized - on clinical practice, on medical expertise, on outcome assessment, on valuations of medical services, and on experiences of illness - less attention has been paid to the process of developing metrics. This article examines the attempt to create severity scales during the revision to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a case of failed commensuration. Using data from interviews with participants in the DSM-5 revision (n = 30), I reconstruct the problems that emerged in the DSM-5 Task Force's effort to develop viable psychometric instruments to measure severity. Framed as a part of a "paradigm shift" in psychiatry, the revision produced ad hoc, heterogeneous severity scales with divergent logics. I focus on two significant issues of metric construction in this case - diagnostic validity and clinical utility. Typically perceived as technical and conceptual challenges of design, I show how these issues were infused with, and undermined by, professional political dynamics, specifically tensions between medical researchers and clinicians. This case reveals that, despite its association with objectivity and transparency, commensuration encompasses more than identifying, operationalizing, and measuring an entity; it demands the negotiation of extra-scientific, non-empirical concerns that get written into medical metrics themselves.

  18. Detecting the gas bubbles in a liquid metal coolant by means of magnetic flowmeters

    NASA Astrophysics Data System (ADS)

    Mogilner, A. I.; Morozov, S. A.; Zakharov, S. O.; Uralets, A. Yu.

    Solution of some problems of control and diagnosis of circuits with a liquid-metal coolant (LMC) often requires the detection of gas bubbles penetrating the circulation loop. The sources of gas intake can be presented by failed fuel elements in reactor core, failed heat-exchange surfaces in sodium-water steam generators in the secondary circuits, gas capture by circulating coolant from gas circuits. Sometimes the gas is especially injected into circulating coolant to study the dynamics of accumulation and extraction of gas bubbles and to solve research problems related to simulations of emergency situations. The most commonly used methods for gas bubble detection include methods based on measuring coolant electric conductivity. A method for detecting gas bubbles in LMC, based on revealing the change of its electric conductivity is considered. Magnetic flowmeter is used as a detecting element of these changes. Approximate theory for describing spectral and energy noises in signals of a magnetic flowmeter, controlling the flow rate of LMC with gas bubbles is suggested. A new method for signal reading is suggested. Experimental results illustrating the possibility of using the method for measuring the rate of bubble movement and studying the dependence of gas bubble volume on the flow rate of injected gas are presented.

  19. Fuel injection apparatus

    SciTech Connect

    Omori, T.; Sakakibara, S.; Kato, M.; Masuda, A.

    1986-06-10

    A fuel injection apparatus is described for supplying fuel from a fuel tank to at least one combustion chamber of an internal combustion engine, comprising: an injector housing defining therein a pressure cylinder bore, an injection cylinder bore and a timing cylinder bore connected in series with the pressure cylinder bore; a pressure plunger, fitted in the pressure cylinder bore and having one end defining, in the pressure cylinder bore, a pressure pump chamber communicating with the injection cylinder bore and the timing cylinder bore; first fuel supply means for supplying fuel from the fuel tank to the pressure pump chamber; pressurizing means for reciprocating the pressure plunger in the pressure cylinder bore in synchronism with the engine operation so as to pressurize fuel in the pressure pump chamber; an injection plunger, having a diameter smaller than the pressure plunger, fitted in the injection cylinder bore and having two ends defining, in the injection cylinder bore, an injection pump chamber and a first communicating chamber communicating with the pressure pump chamber; second fuel supply means for adjusting the quantity of the fuel from the fuel tank in accordance with engine operation conditions so as to supply the adjusted fuel quantity to the injection pump chamber; injection valve means for injecting the fuel into the fuel pump chamber toward a combustion chamber of the engine when the pressure in the pressure pump chamber is applied to the injection plunger through the first communicating chamber, and the fuel pressure in the injection pump chamber reaches a predetermined injection pressure.

  20. Prevalence of Antibiotic Resistance Genes in Subjects with Successful and Failing Dental Implants. A Pilot Study

    PubMed Central

    Koukos, Georgios; Papadopoulos, Christos; Tsalikis, Lazaros; Sakellari, Dimitra; Arsenakis, Minas; Konstantinidis, Antonios

    2015-01-01

    Objectives : To investigate the prevalence of the bacterial genes encoding resistance to beta-lactams, tetracyclines and metronidazole respectively, in subjects with successful and failing dental implants and to assess the presence of Staphylococcus aureus and the mecA gene encoding for Methicillin Resistant Staphylococcus aureus (MRSA) in the same samples. Materials and Methodology: The subject sample included 20 participants with clinically healthy osseointegrated implants and 20 participants with implants exhibiting peri-implantitis. Clinical parameters were assessed with an automated probe, samples were collected from the peri-implant sulcus or pocket and analyzed with Polymerase Chain Reaction for blaTEM, tetM, tetQ and nim genes, S. aureus and MRSA using primers and conditions previously described in the literature. Results: Findings have shown high frequencies of detection for both groups for the tetracycline resistance genes tetM (>30%), tetQ (>65%) with no statistical differences between them (z-test with Bonferroni corrections, p<0.05). The blaTEM gene, which encodes resistance to beta-lactams, was detected in <15% of the samples. The nim gene, which encodes resistance to metronidazole, S.aureus and the mecA gene encoding for MRSA were not detected in any of the analyzed samples. Conclusions: Healthy peri-implant sulci and peri-implantitis cases often harbor bacterial genes encoding for resistance to the tetracyclines and less often for beta-lactams. Thus, the antimicrobial activity of the tetracyclines and to a lower extent to beta-lactams, might be compromised for treatment of peri-implantitis. Since no metronidazole resistance genes were detected in the present study, its clinical use is supported by the current findings. S.aureus may not participate in peri-implant pathology. PMID:25646133

  1. Change Detection: Training and Transfer

    PubMed Central

    Gaspar, John G.; Neider, Mark B.; Simons, Daniel J.; McCarley, Jason S.; Kramer, Arthur F.

    2013-01-01

    Observers often fail to notice even dramatic changes to their environment, a phenomenon known as change blindness. If training could enhance change detection performance in general, then it might help to remedy some real-world consequences of change blindness (e.g. failing to detect hazards while driving). We examined whether adaptive training on a simple change detection task could improve the ability to detect changes in untrained tasks for young and older adults. Consistent with an effective training procedure, both young and older adults were better able to detect changes to trained objects following training. However, neither group showed differential improvement on untrained change detection tasks when compared to active control groups. Change detection training led to improvements on the trained task but did not generalize to other change detection tasks. PMID:23840775

  2. Anatomic Localization and Autonomic Modulation of AV Junctional Rhythm in Failing Human Hearts

    PubMed Central

    Fedorov, Vadim V.; Ambrosi, Christina M.; Kostecki, Geran; Hucker, William J.; Glukhov, Alexey V.; Wuskell, Joseph P.; Loew, Leslie M.; Moazami, Nader; Efimov, Igor R.

    2011-01-01

    Background The structure-function relationship in the atrioventricular junction (AVJ) of various animal species has been investigated in detail, however less is known about the human AVJ. In this study, we performed high-resolution optical mapping of the human AVJ (n=6) to define its pacemaker properties and response to autonomic stimulation. Methods and Results Isolated, coronary-perfused AVJ preparations from failing human hearts (n=6, 53±6 years) were optically mapped using the near-infrared, voltage-sensitive dye, di-4-ANBDQBS, with isoproterenol (Iso, 1 μM) and acetylcholine (ACh, 1μM). An algorithm detecting multiple components of optical action potentials was used to reconstruct multi-layered intramural AVJ activation and to identify specialized slow and fast conduction pathways (SP and FP). The anatomical origin and propagation of pacemaker activity was verified via histology. Spontaneous AVJ rhythms of 29±11 bpm (n=6) originated in the nodal-His region (NH, n=3) and/or the proximal His bundle (H, n=4). Iso accelerated the AVJ rhythm to 69±12 bpm (n=5); shifted the leading pacemaker to the transitional cell (TC) regions near the FP and SP (n=4) and/or coronary sinus (n=2); and triggered reentrant arrhythmias (n=2). ACh (n=4) decreased the AVJ rhythm to 18±4 bpm; slowed FP/SP conduction leading to block between the AVJ and atrium; and shifted the pacemaker to either the TC or TC/NH (bifocal activation). Conclusions We have demonstrated that the AVJ pacemaker in failing human hearts is located in the NH or H-regions and can be modified with autonomic stimulation. Moreover, we found that both the FP and SP are involved in anterograde and retrograde conduction. PMID:21646375

  3. The EPA National Fuels Surveillance Network. I. Trace constituents in gasoline and commercial gasoline fuel additives.

    PubMed Central

    Jungers, R H; Lee, R E; von Lehmden, D J

    1975-01-01

    A National Fuels Surveillance Network has been established to collect gasoline and other fuels through the 10 regional offices of the Environmental Protection Agency. Physical, chemical, and trace element analytical determinations are made on the collected fuel samples to detect components which may present an air pollution hazard or poison exhaust catalytic control devices. A summary of trace elemental constituents in over 50 gasoline samples and 18 commercially marketed consumer purchased gasoline additives is presented. Quantities of Mn, Ni, Cr, Zn, Cu, Fe, Sb, B, Mg, Pb, and S were found in most regular and premium gasoline. Environmental implications of trace constituents in gasoline are discussed. PMID:1157783

  4. Antibodies to meningococcal H.8 (Lip) antigen fail to show bactericidal activity.

    PubMed

    Bhattacharjee, A K; Moran, E E; Zollinger, W D

    1990-02-01

    Purified H.8 (Lip) antigen was coupled to tresyl-activated Sepharose 4B and used in affinity columns to purify anti-Lip antibodies from convalescent patient sera and from immune rabbit sera. Affinity-purified anti-Lip antibodies isolated from two convalescent patient sera contained 1000 and 1280 ELISA units of antibody and included antibodies of IgG, IgA, and IgM isotypes. An anti-Lip mouse monoclonal ascites (2-1-CA2) had 28,400 ELISA units of antibody. Bactericidal assays were performed using three different case strains of Neisseria meningitidis group B, namely 44/76, 8532, and 8047. Neither preparation of purified human anti-Lip antibodies had detectable bactericidal activity against strains 44/76 and 8532, but one of the two had a titer of 1:4 against strain 8047. Anti-Lip antibodies that were purified from immune rabbit serum and contained 1600 ELISA units of anti-Lip antibodies also failed to show detectable bactericidal activity. The rabbits were immunized with purified Lip antigen and showed specific antibody levels of 2000-2200 units by ELISA, but even the unfractionated sera had little or no bactericidal activity against the test strains. The high titer mouse monoclonal ascites had no bactericidal activity against the test strains. The poor bactericidal activity associated with monoclonal and polyclonal antibodies to the Lip antigen suggest that in spite of other attractive properties it may not be useful as a meningococcal vaccine.

  5. Fail-safe design for large capacity lithium-ion battery systems

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Heon; Smith, Kandler; Ireland, John; Pesaran, Ahmad

    2012-07-01

    A fault leading to a thermal runaway in a lithium-ion battery is believed to grow over time from a latent defect. Significant efforts have been made to detect lithium-ion battery safety faults to proactively facilitate actions minimizing subsequent losses. Scaling up a battery greatly changes the thermal and electrical signals of a system developing a defect and its consequent behaviors during fault evolution. In a large-capacity system such as a battery for an electric vehicle, detecting a fault signal and confining the fault locally in the system are extremely challenging. This paper introduces a fail-safe design methodology for large-capacity lithium-ion battery systems. Analysis using an internal short circuit response model for multi-cell packs is presented that demonstrates the viability of the proposed concept for various design parameters and operating conditions. Locating a faulty cell in a multiple-cell module and determining the status of the fault's evolution can be achieved using signals easily measured from the electric terminals of the module. A methodology is introduced for electrical isolation of a faulty cell from the healthy cells in a system to prevent further electrical energy feed into the fault. Experimental demonstration is presented supporting the model results.

  6. Fail-Safe Design for Large Capacity Lithium-Ion Battery Systems

    SciTech Connect

    Kim, G. H.; Smith, K.; Ireland, J.; Pesaran, A.

    2012-07-15

    A fault leading to a thermal runaway in a lithium-ion battery is believed to grow over time from a latent defect. Significant efforts have been made to detect lithium-ion battery safety faults to proactively facilitate actions minimizing subsequent losses. Scaling up a battery greatly changes the thermal and electrical signals of a system developing a defect and its consequent behaviors during fault evolution. In a large-capacity system such as a battery for an electric vehicle, detecting a fault signal and confining the fault locally in the system are extremely challenging. This paper introduces a fail-safe design methodology for large-capacity lithium-ion battery systems. Analysis using an internal short circuit response model for multi-cell packs is presented that demonstrates the viability of the proposed concept for various design parameters and operating conditions. Locating a faulty cell in a multiple-cell module and determining the status of the fault's evolution can be achieved using signals easily measured from the electric terminals of the module. A methodology is introduced for electrical isolation of a faulty cell from the healthy cells in a system to prevent further electrical energy feed into the fault. Experimental demonstration is presented supporting the model results.

  7. Fuel cell market applications

    SciTech Connect

    Williams, M.C.

    1995-12-31

    This is a review of the US (and international) fuel cell development for the stationary power generation market. Besides DOE, GRI, and EPRI sponsorship, the US fuel cell program has over 40% cost-sharing from the private sector. Support is provided by user groups with over 75 utility and other end-user members. Objectives are to develop and demonstrate cost-effective fuel cell power generation which can initially be commercialized into various market applications using natural gas fuel by the year 2000. Types of fuel cells being developed include PAFC (phosphoric acid), MCFC (molten carbonate), and SOFC (solid oxide); status of each is reported. Potential international applications are reviewed also. Fuel cells are viewed as a force in dispersed power generation, distributed power, cogeneration, and deregulated industry. Specific fuel cell attributes are discussed: Fuel cells promise to be one of the most reliable power sources; they are now being used in critical uninterruptible power systems. They need hydrogen which can be generated internally from natural gas, coal gas, methanol landfill gas, or other fuels containing hydrocarbons. Finally, fuel cell development and market applications in Japan are reviewed briefly.

  8. Diesel fuel injection system

    SciTech Connect

    Schechter, M.M.; Simko, A.O.

    1986-04-22

    A fuel injection pump is described of the multiple plunger spill port type for an automotive type internal combustion engine, the pump including at least four axially spaced engine camshaft driven pump plungers grouped in pairs and sequentially and in succession moved in one direction through a fuel pumping stroke and oppositely through a fuel intake stroke. A fuel pressurization/supply chamber is contiquous to the end of each plunger for pressurization of the fuel therein or supply of fuel thereto from a supply passage upon coordinate movement of the plunger, fill/spill passage means connected to a single fuel return spill port and in parallel flow relationship to each of the plunger bores as a function of the position of the plungers, each plunger having a pair of internal passages connected at all times to its chamber and alternately alignable with the supply or fill/spill passage means as a function of the position of the plunger. A fuel discharge passage is operatively connecting each of the chambers to an individual engine cylinder, a single spill port control valve movable to block or permit the spill of fuel through the spill port to a return line to control the pressurization of fuel in all of the fuel chambers and associated discharge passages, a single solenoid connected to the spill control valve for moving it to block or unblock the spill port, and a single shuttle valve operatively associated with all of the fill/spill passage means and spill port reciprocably movable between positions to sequentially connect the plunger chambers one at a time in succession to the spill port during the pumping pressurization stroke of its plunger for the injection of fuel to an individual cylinder while the other chambers are in various stages of being refilled with fuel and preparing for pressurization upon successive actuation of the plungers by the camshaft.

  9. Wear mechanism evaluation and measurement in fuel-lubricated components

    NASA Astrophysics Data System (ADS)

    Lacey, Paul I.

    1994-09-01

    Previous studies have demonstrated that the durability of some fuel injection systems on compression-ignition engines will be adversely affected by fuels of sufficiently low lubricity. However, no widely accepted lubricity measure is available; indeed, the wear mechanisms present have not been conclusively defined. The results of the present study indicate that oxidative corrosion is the predominant mechanism with very highly processed fuels, resulting in catastrophic wear and rapid failure. A laboratory test procedure directed toward the oxidative wear mechanism was evaluated and a number of modifications suggested. Two closely related laboratory wear test procedures that rely on the transition from mild boundary lubricated wear to adhesive scuffing were also developed. The resulting procedures allow the fuels to be either ranked using a continuous scale or separated using a simple pass/fail criteria. All the procedures are sensitive to the addition of trace quantities of lubricity additives and show directional correlation with refinery severity, as measured by sulfur and aromatic content. As a result, the tests produced excellent correlation with full-scale equipment tests performed at a number of locations, as well as the criteria necessary for oxidative corrosion. However, the scuffing load tests show greatly increased separation between good and unacceptable fluids compared to the oxidative corrosion tests. Evaluation of commercially available fuels indicates that fuel lubricity is decreasing and that very poor lubricity fuels are occasionally observed.

  10. Alternative fuels for road vehicles

    SciTech Connect

    Poulton, M.L.

    1994-12-31

    The finite nature of global fossil fuel resources underscores the need to develop alternative vehicular fuels. Increased use of renewable and alternative fuels can extend fossil fuel supplies and help resolve air pollution problems inherent in automotive use of conventional fuels. Fuel characteristics, safety implications, feedstocks, infrastructure, fuel production costs, emissions performance, required vehicle modifications, and outlook are described for LPG, reformulated gasoline, natural gas, hydrogen, electricity, biofuels, ethanol, and methanol. 26 fig., 288 refs., 29 tabs.

  11. Fuel cell generator with fuel electrodes that control on-cell fuel reformation

    DOEpatents

    Ruka, Roswell J.; Basel, Richard A.; Zhang, Gong

    2011-10-25

    A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

  12. Fuel/hydraulic transfer valve improves reliability of Atlas space launch vehicle

    NASA Technical Reports Server (NTRS)

    Ogman, M.

    1980-01-01

    The Atlas fuel hydraulic transfer valve design is described. The design satisfies primary goals such as fuel and oil isolation before launch in order to use existing ground support and airborne hardware and procedures. The valve operates only after the vehicle has been committed to launch. Hydraulic system function is maintained if the valve fails to function. Valve operation is mechanical and interfaces only with the propulsion system.

  13. REACTOR FUEL SCAVENGING MEANS

    DOEpatents

    Coffinberry, A.S.

    1962-04-10

    A process for removing fission products from reactor liquid fuel without interfering with the reactor's normal operation or causing a significant change in its fuel composition is described. The process consists of mixing a liquid scavenger alloy composed of about 44 at.% plutoniunm, 33 at.% lanthanum, and 23 at.% nickel or cobalt with a plutonium alloy reactor fuel containing about 3 at.% lanthanum; removing a portion of the fuel and scavenger alloy from the reactor core and replacing it with an equal amount of the fresh scavenger alloy; transferring the portion to a quiescent zone where the scavenger and the plutonium fuel form two distinct liquid layers with the fission products being dissolved in the lanthanum-rich scavenger layer; and the clean plutonium-rich fuel layer being returned to the reactor core. (AEC)

  14. Spiral cooled fuel nozzle

    DOEpatents

    Fox, Timothy; Schilp, Reinhard

    2012-09-25

    A fuel nozzle for delivery of fuel to a gas turbine engine. The fuel nozzle includes an outer nozzle wall and a center body located centrally within the nozzle wall. A gap is defined between an inner wall surface of the nozzle wall and an outer body surface of the center body for providing fuel flow in a longitudinal direction from an inlet end to an outlet end of the fuel nozzle. A turbulating feature is defined on at least one of the central body and the inner wall for causing at least a portion of the fuel flow in the gap to flow transverse to the longitudinal direction. The gap is effective to provide a substantially uniform temperature distribution along the nozzle wall in the circumferential direction.

  15. Alcohol fuels for aviation

    SciTech Connect

    Schauffler, P.

    1982-06-01

    The ten-fold increase in aviation fuel prices in eight years has caused a reassessment of alcohol fuels. In a recent test, methanol fuel-flow rate was high at takeoff, and levelled off at 10,000 feet, but above 18,000 fell 30% below avgas use. Because methanol sells thirty cents below avgas per gallon it is already an attractive fuel for piston-engine aircraft. But as 95% of aviation fuel is burned as kerosene in turbines a test program has been set up to look at the performance of small shaft turbine engines with various combinations of alcohols and water, and of straight methanol, and to look at major thrust engine at optimum fuel as well. These tests should determine the overall alcohol potentials for aviation. The tests will also tell if the breakthrough will be modest or major.

  16. Fuel Tank Technology

    DTIC Science & Technology

    1989-11-01

    structures b) - Equal thermic inertia c) - Equal fluid volume d) - Equal pressure variation on both wings at the change of the room temperature - This...individual fuel sections. Each fuel section is further ccmpartmentated by metall tank shear walls and tank floors into three individual fuel cells to...plate Dy a stretch forming process, and the metallic tank floors . The air intake segments extend from one bulkhead to the other, thus reducing assembly

  17. Liquid fuel cells.

    PubMed

    Soloveichik, Grigorii L

    2014-01-01

    The advantages of liquid fuel cells (LFCs) over conventional hydrogen-oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented.

  18. Fuels Combustion Research.

    DTIC Science & Technology

    1984-07-18

    uncertainties in the future sources and characteristics of fuels has emphasized the need to better understand fuel effects on combustion , e.g. energy release...experimentally to be made. Unsuccessful comparisons can lead to impro- vements in modelling concepts . Two simplified models for the combustion of slurry...AD-A149 186 FUELS COMBUSTION RESEACCH(U) PRINCETON UNIV NJ DEPT OF i/i MECHANICAL AND AEROSPACE ENGINEERING F L DRYER ET AL. 18 JUL 84 NAE-i668 AFOSR

  19. Food for fuel

    SciTech Connect

    Bell, J.

    1982-05-01

    Cassava, sugar cane, grain crops, molasses - all are potential feedstocks for ethanol production. Brazil has taken a clear lead in converting food crops into ethanol fuels for the automobile, but other countries may follow and the economic consequences could be considerable. This article looks at the various options. The total activity involved in fuel ethanol production and usage is considered as comprising three related components: feedstock production, ethanol production and application of the ethanol as a transport fuel.

  20. Alternative Fuels Infrastructure Development

    SciTech Connect

    Bloyd, Cary N.

    2010-06-30

    This summary reviews the status of alternate transportation fuels development and utilization in Thailand. An understanding of the issues and experiences associated with the introduction of alternative fuels in other countries can help the US in anticipation potential problems as it introduces new automotive fuels. Thailand is of particular interest since it introduced E20 to its commercial market in 2007 and the US is now considering introducing E20 into the US market.